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Member since Dec-31-08 · Last seen Oct-20-19
About Me (in case you care):

Old timer from Fischer, Reshevsky, Spassky, Petrosian, etc. era. Active while in high school and early college, but not much since. Never rated above low 1800s and highly erratic; I would occasionally beat much higher rated players and equally often lose to much lower rated players. Highly entertaining combinatorial style, everybody liked to play me since they were never sure what I was going to do (neither did I!). When facing a stronger player many try to even their chances by steering towards simple positions to be able to see what was going on. My philosophy in those situations was to try to even the chances by complicating the game to the extent that neither I nor the stronger player would be able to see what was going on! Alas, this approach no longer works in the computer age. And, needless to say, my favorite all-time player is Tal.

I also have a computer background and have been following with interest the development in computer chess since the days when computers couldn't always recognize illegal moves and a patzer like me could beat them with ease. Now itís me that canít always recognize illegal moves and any chess program can beat me with ease.

But after about 8 years (a lifetime in computer-related activities) of playing computer-assisted chess, I think I have learned a thing or two about the subject. I have conceitedly defined "AylerKupp's corollary to Murphy's Law" (AKC2ML) as follows:

"If you use your engine to analyze a position to a search depth=N, your opponent's killer move (the move that will refute your entire analysis) will be found at search depth=N+1, regardless of the value you choose for N."

Iím also a food and wine enthusiast. Some of my favorites are German wines (along with French, Italian, US, New Zealand, Australia, Argentina, Spain, ... well, you probably get the idea). One of my early favorites were wines from the Ayler Kupp vineyard in the Saar region, hence my user name. Here is a link to a picture of the village of Ayl with a portion of the Kupp vineyard on the left:

You can send me an e-mail whenever you'd like to aylerkupp

And check out a picture of me with my "partner", Rybka (Aylerkupp / Rybka) from the Masters - Machines Invitational (2011). No, I won't tell you which one is me.


Ratings Inflation

I have become interested in the increase in top player ratings since the mid-1980s and whether this represents a true increase in player strength (and if so, why) or if it is simply a consequence of a larger chess population from which ratings are derived. So I've opened up my forum for discussions on this subject.

I have updated the list that I initially completed in Mar-2013 with the FIDE rating list through 2018 (published in Jan-2019), and you can download the complete data from It is quite large (~ 213 MB) and to open it you will need Excel 2007 or later version or a compatible spreadsheet since several of the later tabs contain more than 65,536 rows.

The spreadsheet also contains several charts and summary information. If you are only interested in that and not the actual rating lists, you can download a much smaller (~ 1 MB) spreadsheet containing the charts and summary information from You can open this file with a pre-Excel 2007 version or a compatible spreadsheet.

FWIW, after looking at the data I think that ratings inflation, which I define to be the unwarranted increase in ratings not necessarily accompanied by a corresponding increase in playing strength, is real, but it is a slow process. I refer to this as my "Bottom Feeder" hypothesis and it goes something like this:

1. Initially (late 1960s and 1970s) the ratings for the strongest players were fairly constant.

2. In the 1980s the number of rated players began to increase exponentially, and they entered the FIDE-rated chess playing population mostly at the lower rating levels. Also, starting in 1992, FIDE began to periodically lower the rating floor (the lowest rating for which players would be rated by FIDE) from 2200 to the current 1000 in 2012. This resulted in an even greater increase in the number of rated players. And the ratings of those newly-rated players may have been higher than they should have been, given that they were calculated using a high K-factor.

3. The ratings of the stronger of these players increased as a result of playing these weaker players, but their ratings were not sufficiently high to play in tournaments, other than open tournaments, where they would meet middle and high rated players.

4. Eventually they did. The ratings of the middle rated players then increased as a result of beating the lower rated players, and the ratings of the lower rated players then leveled out and even started to decline. You can see this effect in the 'Inflation Charts' tab, "Rating Inflation: Nth Player" chart, for the 1500th to 5000th rated player.

5. Once the middle rated players increased their ratings sufficiently, they began to meet the strongest players. And the cycle repeated itself. The ratings of the middle players began to level out and might now be ready to start a decrease. You can see this effect in the same chart for the 100th to 1000th rated player.

6. The ratings of the strongest players, long stable, began to increase as a result of beating the middle rated players. And, because they are at the top of the food chain, their ratings, at leas initially, continued to climb. I think that they will eventually level out and may have already done that except for possibly the very highest rated players (rated among the top 50) but if this hypothesis is true there is no force to drive them down so they will now stay relatively constant like the pre-1986 10th rated player and the pre-1981 50th rated player. When this leveling out will take place, if it does, and at what level, I have no idea. But a look at the 2017 ratings data indicates that, indeed, it has already started, maybe even among the top 10 rated players.

You can see in the chart that the rating increase, leveling off, and decline first starts with the lowest ranking players, then through the middle ranking players, and finally affects the top ranked players. As of today the average ratings of ALL the players, including the average of the Top-10 rated players, has been fairly constant since 2014.

It's not precise, it's not 100% consistent, but it certainly seems evident. And the process takes decades so it's not easy to see unless you look at all the years and many ranked levels.

Of course, this is just a hypothesis and the chart may look very different 20 years from now. But, at least on the surface, it doesn't sound unreasonable to me.

But looking at the data through 2018 it is even more evident that the era of ratings inflation appears to be over, unless FIDE once more lowers the rating floor and a flood of new and unrated players enters the rating pool. The previous year's trends have either continued or accelerated; the rating for every ranking category has either flattened out or has started to decline as evidenced by the trendlines.


Chess Engine Non-Determinism

I've discussed chess engine non-determinism many times. If you run an analysis of a position multiple times, with the same engine, the same computer, and to the same search depth, you will get different results. Not MAY, WILL. Guaranteed. Similar results were reported by others.

I had a chance to run a slightly more rigorous test and described the results starting here: US Championship (2017) (kibitz #633). I had 3 different engines (Houdini 4, Komodo 10, and Stockfish 8 analyze the position in W So vs Onischuk, 2017 after 13...Bxd4, a highly complex tactical position. I made 12 runs with each engine; 3 each with threads=1, 2, 3, and 4 on my 32-bit 4-core computer with 4 MB RAM and MPV=3. The results were consistent with each engine:

(a) With threads=1 (using a single core) the results of all 3 engines were deterministic. Each of the 3 engines on each of the analyses selected the same top 3 moves for each engine, with the same evaluations, and obviously the same move rankings.

(b) With threads =2, 3, and 4 (using 2, 3, and 4 cores) none of the engines showed deterministic behavior. Each of the 3 engines on each of the analyses occasionally selected different analyses for the same engine, with different evaluations, and different move rankings.

I've read that the technical reason for the non-deterministic behavior is the high sensitivity of the alpha-beta algorithms that all the top engines use to move ordering in their search tree, and the variation of this move ordering using multi-threaded operation when each of the threads gets interrupted by higher-priority system processes. I have not had the chance to verify this, but there is no disputing the results.

What's the big deal? Well if the same engine gives different results each time it runs, how can you determine what's the real "best" move? Never mind that different engines or relatively equal strength (as determined by their ratings) give different evaluations and move rankings for their top 3 move and that the evaluations may differ as a function of the search depth.

Since I believe in the need to run analyses of a given position using more than one engine and then aggregating the results to try to reach a more accurate assessment of a position, I typically have run sequential analyses of the same position using 4 threads and a hash table = 1,024 MB. But since I typically run 3 engines, I found it to be more efficient to run analyses using all 3 engines concurrently, each with a single thread and a hash table = 256 MB (to prevent swapping to disk). Yes, running with a single thread runs at 1/2 the speed of running with 4 threads but then running the 3 engines sequentially requires 3X the time and running the 3 engines concurrently requires only 2X the time for a 50% reduction in the time to run all 3 analyses to the same depth, and resolving the non-determinism issues.

So, if you typically run analyses of the same position with 3 engines, consider running them concurrently with threads=1 rather than sequentially with threads=4. You'll get deterministic results in less total time.


A Note on Chess Engine Evaluations

All engines provide different evaluations of the next "best" move, sometimes significantly different. For example, Stockfish's evaluations tend to be higher than other top engines and Houdini's evaluations tend to be lower. This could be because Stockfish typically reaches greater search depths than the other top engines in the same amount of time, and Houdini's typically reaches lower search than the other top engines. Or it could be for other reasons.

If we are analyzing a position we typically want to use the "best" engine as "measured" by its rating,, and that's currently (Mar-2018) Stockfish 10 for "classic" chess engines (I'm deliberately excluding AlphaZero and Leela Chess Zero because they use a different move/search tree branch evaluation approach and the best versions of them use either TPU or GPU support to enhance their calculation capability and therefore are not directly comparable), and it's higher rating has been achieved in engine vs. engine tournaments such as CCRL and CEGT. But the "best" engine as determined by playing head-to-head games is not necessarily the best engine for <analysis> since in analysis we not only want to know the best moves from a given position but we want an accurate <evaluation> of the position. Specifically, we want an accurate evaluation of the position in <absolute> terms in order to determine whether one side has a likely winning advantage (generally an absolute evaluation > [ ±2.00] or 2 pawns), a significant advantage (generally an absolute evaluation in the range [ ±1.00] to [ ±1.99], a slight advantage (generally an absolute evaluation in the range [ ±0.50] to [ ±0.99], of if the position is approximately equal (generally an absolute evaluation in the range [-0.49 to +0.49]).

But when playing a game an accurate <absolute> evaluation is irrelevant, what counts is an accurate <relative> evaluation. This is because all chess engines using the minimax algorithm to determine the best move (assuming best play by both sides) do that by a series of pairwise comparisons between two moves. So if an engine is trying to determine which of 2 moves, A and B is better, it doesn't matter if their evaluations are [+12.00] or [+11.00], [+1.20] or [+1.10], or [+0.12] or [+0.11], it will always select move A as the better move and consider that branch in the search tree to be the better line. So multiplying 2 evaluations by a fixed constant or adding a fixed constant to 2 evaluations has no effect in the engine determining which of the 2 moves is better. But clearly, evaluations of [+12.00], [+1.20], or [+0.12] will give the analyst much different impressions of the position.

In practice the discrepancies in evaluations between several engines is not that drastic, but I suggest that you don't assume that Stockfish's <absolute> evaluations are the most accurate just because it is (currently) the best "classical" game-playing engine (i.e. not using GPU or TPU support) or because it reached the greater search depth in a given amount of time.


Any comments, suggestions, criticisms, etc. are both welcomed and encouraged.

------------------- Full Member

   AylerKupp has kibitzed 12555 times to chessgames   [more...]
   Oct-20-19 Grand Swiss IoM (2019) (replies)
AylerKupp: <<Gypsy> Matlakov may have a draw fortress.> Not according to the Lomonosov tablebases. Of course it's only a theoretical win for White, it's always possible that Carlsen will make a mistake somewhere along the line. But with such a simplified position and plenty of ...
   Oct-20-19 N Pokern vs M Bassler, 1981 (replies)
AylerKupp: According to Stockfish 10, after 44.fxe6 [DIAGRAM] ... almost anything wins. At d=35 Stockfish evaluated its 5 top moves as follows, with all the evaluations increasing: 44...Rd1+: [-8.45] 44...Kg8: [-8.35] 44...Rc8: [-7.60] 44...Re8: {-7.44] 44...e4: [-6.09] My ...
   Oct-19-19 D A Yeager vs Stripunsky, 2008 (replies)
AylerKupp: <<thegoodanarchist> The only thing this man did is to say Jagermeister doesn't work as a pun.> You obviously either didn't get it or choose to ignore it. The reason I took him to task has nothing to do with his opinion that "Yeagermaster would've worked, Jagermeister ...
   Oct-17-19 McShane vs Caruana, 2019 (replies)
AylerKupp: <<Marksen> 52.Qg4! would have won on the spot because of the threat Qh5+. 52.- Kg8 53.Re6! and most of black pieces are hanging. Unfortunately Luke played 52.Qg5? > As you see from my response to <cro777> above White wins after either 52.Qg4 or 52.Qg5 as actually
   Oct-13-19 Kholmov vs Hort, 1967 (replies)
AylerKupp: <<rogl> With 7-men tablebases we can get a verdict of 'draw or not draw?'> We can do better than that, if we have the patience and sufficient disk space. The position after 44...Nxh8 is amenable to analysis by the FinalGen tablebase generator. Unfortunately on my ...
   Oct-12-19 Fischer - Taimanov Candidates Quarterfinal (1971) (replies)
AylerKupp: <The Boomerang> I read or heard that it was the first shutout in 50 years, what was the other one if it happened?> It depends on whether you consider that a specific minimum number of games is required to be considered a "shutout" since in the recent World Cup there were ...
   Oct-09-19 World Cup (2019) (replies)
AylerKupp: <Pedro Fernandez> No, I did not! And having guitars in the orchestra is very unusual, I had not seen that before. But I miss the battleship though.
   Oct-05-19 Russian Chess Circle
AylerKupp: <Pyrandus> A Russian Chess Circle, like all other circles, has no end.
   Oct-03-19 F Frilling vs J L Watson, 1969 (replies)
AylerKupp: The Dragon still breathes fire!
   Oct-02-19 beatgiant chessforum
AylerKupp: <beatgiant> I don't see any difference either between becoming a good (maybe I should have said great) player and achieving highor top ratings. Only the good players will achieve high ratings and only the great players will achieve top ratings. Yes, the realistic candidates ...
(replies) indicates a reply to the comment.

De Gustibus Non Disputandum Est

Kibitzer's Corner
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Premium Chessgames Member
  virginmind: Hi <AylerKupp>, great wines in the Cochem region too - I stayed there for a week and the owner of the house had a vineyard in the area. We most probably passed through Ayl once, while going from Trier to Saarburg.
Premium Chessgames Member
  AylerKupp: <virginmind> Thanks. I am not familiar with the wines from Cochem. In fact, I had never heard of them and they are not mentioned in any of my wine books. After a little research I found that they're from a region in the Mosel usually dismissed by wine writers, probably unjustifiably, particularly in hot years. But I suspect that there are an almost infinite number of unknown small regions in the world where the combination of soil, weather, and tradition allows fine wine to be made in small quantities. It would be impossible for anyone to be familiar with even a majority of them.

I'm fairly sure that if you went from Trier to Saarburg that you passed though Ayl as it is on the main road between the two just north of Saarburg. And the Ayl vineyard is just north of the city of Saarburg. Someday I hope to travel through the German wine regions, at least the major ones.

You've just whetted my appetite. I think I'll go down to my cellar and chill a bottle of German wine for dinner.

Premium Chessgames Member
  virginmind: I guess others around may be better known. We just missed a wine festival which took place in Cochem a few days before. I don't drink much, but of course I'm aware of Riesling. Vineyards were scattered pretty much everywhere along the Mosel valley, but we were mostly interested in castles and such - amazing touristic region.

Actually, close to where I live (Iasi), there is Cotnari vineyard, which is rather famous in Romania for its wines - maybe you heard of it too?

Premium Chessgames Member
  AylerKupp: <virginmind> I am not too familiar with eastern European wines and I have never had a Romanian wine. In fact, I have never heard of any of them. I have had Hungarian wines, Tokaj for sure (I even have some in my cellar since they live a long time) and some dry white wines from Lake Balaton but that was a long time ago. And (I think) I've had some Croatian wines as well. Plus some Austrian wines, mainly Riesling and Gruner Veltliner.

The large wine store where I do most of my wine buying (I'm good friends with the owner) doesn't carry any. I live in Los Angeles, CA and searching the web for Romanian wine retailers in Los Angeles didn't show any. So it doesn't look like I will have an opportunity to try any time soon. I may have to wait until I visit Romania.

I did find a reference to Romanian wines in what I consider to the best book about wine ever written by far (I have 5 different editions dating back to the first one in 1971!), "The World Atlas of Wine" by Hugh Johnson and Jancis Robinson does have 2 pages (and that's all!) covering Romanian wines. But that's 2 more pages than any of my other wine books! It does have 4 pages of Hungarian wines, 1 page of Czech Republic and Slovakian wines, 1 page of what they call "Western Balkans" (Bosnia, Serbia, Albania, Montenegro, and the Republic of Macedonia), 2 pages on Croatian wines 2 pages on Slovenian wines, and 2 pages on Bulgarian wines besides the 2 pages on Romanian wines. So that's 14 pages of eastern European wines. If you are interested in learning about wines from all over the world I cannot recommend this book more highly, although it's a little bit pricey, £ 40 per the back cover although I might have gotten it at a discount.

As it's title implies the book is full of beautiful and clear color maps of each and every wine region covered. It shows both the Cotari region and winery as well as Iasi. The Cotari winery has a nice web page although, of course, it is oriented towards selling wine. A little more research showed me that Cotari is known for its sweet white wines and that they seem to age reasonably well.

I did find the location of the Consulate General of Romania in Los Angeles which happens to be not far from where I buy most of my wines but, needless to say, they didn't advertise any Romanian wine (or any other wine for that matter!) for sale.

Premium Chessgames Member
  virginmind: Los Angeles!? I thought you're from the Saar region! Well, that makes sense why no Cotnari (as it's spelled, not Cotari) wine over there, it's a bit far away. Although I suspect there may be some Romanian wines imported somewhere in California...Oh well, ha ha, right, I wouldn't expect our consulate to sell or advertise wines...

Come to think of it, Cotnari winery is also sponsoring our local chess club, Politehnica Iasi. In fact, there's a bottle of "Feteasca Alba" of Cotnari on our kitchen table right now but, as I said, I don't drink much - I get headaches from it. It's indeed semi-sweet, although Cotnari also produce a dry wine, "Francusa".

It's pretty obvious from what you write that wines are indeed a big passion for you, congratulations! I can only imagine how such a tasty passion can warm your life. I doubt I will buy that book any time soon, but thanks for signalling it to me.

Actually you're right, apparently no trace of Cotnari selling in California, but I found a link for a reseller in Niles, Illinois (coincidence, it's the American state I've been staying in for a year, back in 1994-95): Bottles are pretty cheap as you can see and you may want to order a couple just for a taste of sweet Moldavian hills :) (Moldova is the name of the Romanian province where Iasi and Cotnari are situated - not to be confused with Moldova, a country neighboring Romania, which once used to form together a bigger Moldova. But that's another story.)

Premium Chessgames Member
  AylerKupp: <virginmind> All my references do say "Cotnari" and not "Cotari" so I guess that I just dropped the "t" when I wrote it down. And my spell checker didn't have either word in its database so it was useless in detecting the error. Sorry about that.

But I did find a source of Romanian wines at a wine store not far from me at very low prices, all from Recas Castle winery. They have the international varieties Pinot Noir, Cabernet Sauvignon, and Pinot Grigio which would be interesting to try to see how they compare with the same grapes from regions I'm familiar with as well as Romanian varieties like Feteasca Regala (white, presumably dry) and Feteasca Neagra (which even I can tell from the name that it's red). Even more interesting they have two single-vineyard Feteasca Neagra and Cabernet wines, which should be more distinctive than the generic versions of the same varietals.

Yes, I'm fairly passionate about wines. I was introduced to fine wine by my future father-in-law almost 50 years ago when I was in college and have been passionate ever since. Since I didn't have much money in those days we struck a deal, I would wash his car for 1 bottle and I would wax it for 3 bottles. And my interest in his daughter also lasted since we celebrated our 47th wedding anniversary in late December of last year and this March we will be celebrating the 50th anniversary of the day we met.

Too bad about wine giving you a headache. Some of my friends get headaches after drinking red wine but not after drinking white wine but unfortunately that's not the case with you. I've found that taking some aspirin before or right after drinking wine seems to help them. Fortunately I seem to be "immune" to the problem. You might also try wine made from grapes low in tannin such as Pinot Noir and Gamay, the latter from Beaujolais. I like to cook and I typically use these or Zinfandel (a local California wine) when making stews because they are low in tannin and so don't become bitter when reduced in volume during cooking.

And, as a student of history and European history in particular, I am familiar with the history and "evolution" of Moldavia/Moldova/Bessarabia/Wallachia/Dobruja/Bu- kovina, etc., so I wouldn't be one to confuse them. Another story, as you said. I did find the following interesting *.gif graphically summarizing the historical expansion/contraction of Romanian territory from 1859 through 2010:

Nice chatting with you. The world of chess is such an interesting one and you meet all sorts of nice people although, unfortunately, some not so nice ones as well. But I think it's worth it.

Apr-03-19  MrMelad: Continued discussion from the AlphaZero page

<Trolling, like beauty, is often in the eye of the beholder. ...
as a US Supreme Court Justice once said about pornography, "I can't define it, but I sure recognize it when I see it." Or words to that effect.>

I wouldn't compare your posts to pornography but admittedly sometimes it does feel like that... And not in the good sense! :)

But seriously, by definition trolling is a <deliberate> attempt to provoke. As long as your posts reflect your honest opinion and are not meant to provoke then you are fine by me even if the disagreement continues and the debate becomes circular.

Long posts can be informative or they can be pompous and boring and often they are both. I think that complicated issues often requires long posts and discussions that somtimes range over a lot of time.

"round and round" discussions can sometimes converge as the rounds becomes smaller until they encompass exactly the source of disagreement.

<So I suppose that could put me on your ignore list which, as I've said before, indicates that you have good judgment>

I'm happy that your style is not dependent on what people think of it, but I don't understand your willingness to admit of any wrong doing. People that ignores you doesn't have "good judgement" they have different taste.

There's a psychological approach which I very much agree with, it's called - I'm OK, you are OK. It's basically arguing that people can have 4 different types of interaction with other people:

1. I'm not OK you are not OK
2. I'm not OK you are OK
3. I'm OK you are not OK
4. I'm OK you are OK

The point is that the fourth type of interaction is the best approach to life and most healthy and the first type is the worst.

I hope I don't come off as condescending when I say I recommend both the approach and the book.

<if you don't put me on your ignore list, take the chance that my occasional although infrequent posted pearl of wisdom is worth the aggravation of suffering from reading my verbose and alleged troll-like posts>

I've never considered ignoring you as I've learned from your posts. I think you add a lot to many discussions and topics. I apologize if I gave the wrong impression, I'd like to restate that we have agreed on most of points we've discussed and that I respect your point of view on the things we don't.

In any case, thanks for the debate.

Premium Chessgames Member
  diceman: This is interesting.

I made an improvement on an Uhlmann
game. I also played out a few moves
after the improvement, and came to the conclusion the position was equal.

To test my analysis I ran the game fragment through CG's StockFish.

Here is the position of interest:

click for larger view

White has just played b2 to b4, as you
can see black's bishop is trapped, he must play cxb3 en passant.

Incredibly, the pgn gives cxb3 a question mark, and recommends Bxf2+ ???

Here is the relevant pgn:

<14.b4 cxb3 ? 14...♗xf2+ 15.♖xf2 +- +3.52 (26 ply) 15.Nxb3 = +0.23 (28 ply)>

So StockFish recommends a move for black that's +3.52 @ 26 ply, and questions a move that's +0.23 @ 28 ply.

Exactly the opposite of what it should be doing.

You almost get the idea it doesn't know it can capture en passant. However, since my pgn had cxb3 as the move StockFish says: Yup, it's equal.

I don't know if it's a StockFish issue,
or something to do with CG's StockFish?

Very strange?

Premium Chessgames Member
  AylerKupp: <<MrMelad> Regarding the personal stuff, I've posted in your forum, I hope it's okay with you.>

Absolutely! I welcome any comments to my posts whether I agree with them or not. And my forum is a good place for them. My only concerns are that (a) I don't visit my forum too often so there may be a lag between when someone makes a post and I answer it and (b) sometimes it's not obvious what the context of the post is if it's related to a post on a different page. So please bear with me.

As far as your post above, yes, I can see why you (and others) might consider them to be like pornography, and that's why I like the second definition better. After all, if my posts are like pornography then they must be clear and not fuzzy. Alas, I typically fail at that. But it then becomes a win-win situation, if they are fuzzy, then they are art. ;-)

<"round and round" discussions can sometimes converge as the rounds becomes smaller until they encompass exactly the source of disagreement.>

Unfortunately convergence for these "round and round" discussions is not guaranteed, and we often quickly reach the point of diminishing returns when considered the time and effort put into creating a reasonably well-thought out response. Sometimes it's just best to agree to disagree and move on to other things. After all, "the more you run over a dead cat the flatter it gets." But that's another story.

<don't understand your willingness to admit of any wrong doing.>

That's just another way of trying to break a deadlock. If you take responsibility for wrong doing for a situation, even though you don't think you did anything wrong, that sometimes lets you move on to more important things. After all, who is "right" and who is "wrong" is usually not relevant, it's the issues that are important.

One time during a meeting involving about 15 people I took responsibility for an action. After the meeting my boss' boss asked me "How could that possibly have been you fault?" My response was "It wasn't. But why should 15 people's times be wasted for about 20 minutes trying to determine who was right and who was wrong? Better to get that out of the way without wasting those 15 people's times and get down to the problem that we were trying to solve." I think that my boss' boss liked my attitude.

Premium Chessgames Member
  AylerKupp: <Personal stuff Ė continued>

<There's a psychological approach which I very much agree with, it's called - I'm OK, you are OK. >

I remember that book. But sometimes someone <is> right and someone <is> wrong, and it's important to determine which one is what. Hopefully it can be done constructively and with civility, but it must be done regardless. But there should not be any reason to get personal about it.

The 4 interactions you mentioned reminded me of a chart that I used to present at kick-off meetings for new projects. It was titled "If you do what I say" and it went something like this:

1. If you do what I say and it turns out well, we'll both be praised for our good judgment.

2. If you do what I say and it doesn't turn out well, I'll be blamed for my poor judgment.

3. If you don't do what I say and it turns out well, you'll be praised for your good judgment.

4. If you don't do what I say and it doesn't turn out well, you're screwed.

<I've never considered ignoring you as I've learned from your posts. I think you add a lot to many discussions and topics. I apologize if I gave the wrong impression, I'd like to restate that we have agreed on most of points we've discussed and that I respect your point of view on the things we don't. In any case, thanks for the debate.>

Again, suggesting that people put me on their ignore list is another way of trying to terminate what I consider a less than productive discussion and move on to other things. Besides, since the number of people you can put in your ignore list is limited, I look forward to the quandary those people will eventually face if they eventually try to add someone else to their ignore list and find out that in order to do so they must delete someone from it. Decisions, decisions. :-)

And no, I don't think that you gave me the wrong impression. The main point that I was trying to make was that there are times when you want to know the best implementation (hardware + software) of a solution to a problem and there are times when all you want to know is the best software implementation. That's all. And after all, our motivations and interest for preferring one over the other may change in the near future; "Indecision is the key to flexibility". (same story as the dead cat's story).

Apr-08-19  MrMelad: <AylerKupp> I appreciate the time you invest in your comments and also your positive thinking and optimism. I value your many contributions in this site on many topics.

Regarding our discussion in the AlphaZero page I think it has reached a point where both of us made our best case and we should either wait for others to chip in or just let it be.

Premium Chessgames Member
  AylerKupp: <<BOSTER> What is the difference between usual tree Search for engine (Kotov) and Monte-Carlo Tree Search, based for the AZ?>

First let's make sure we're talking about the same thing. Here is what I think is a summary of the differences between search tree expansion and pruning in both classic engines (per Shannon's original 1949 paper "Programming a Computer for Playing Chess" ( ) as used by Stockfish, Komodo, etc. and an MCTS-like search tree expansion and pruning as used by AlphaZero ("Mastering Chess and Shogi by Self-Play with a General Reinforcement Learning Algorithm", (( (not much on MCTS), "A general reinforcement learning algorithm that masters chess, shogi and Go through self-play" (better), and the "Game Changer" book (the easiest to follow, but ...) by Mathew Sadler and Natasha Regan) and "Technical Explanation of Leela Chess Zero" by Andy Olsen, ). Both AlphaZero articles were written by members of the DeepMind team and they assisted the authors of "Game Changer". Be aware that there are contradictions on how MCTS is implemented in AlphaZero (if at all!) in all 3 papers and the book, so I'm not really sure how AlphaZero implements MCTS or its apparently close derivative, PUCT.

I'm aiming to highlight the similarities between the two approaches (of which, at a high level, there are many) and the differences, although of course there are many details I've left out, mainly because, sadly, I don't know them. :-(

Part 1 of 3: <Classic>

1. Start with the current game position (the search tree root) and identify all legal candidate next moves.

2. Select the "most promising" candidate next moves based on heuristics (which differ from engine to engine). The heuristics represent "educated guesses" as to which moves will be the roots of the branches of the search tree that are most likely to contain the best moves.

3. Evaluate the resulting position for the most promising next moves by means of a hand crafted evaluation function which returns an evaluation function based on centipawns.

4. Expand the tree by repeating the process for all the most promising candidate moves at the next level, an using the alpha-beta pruning algorithm to delete from the search tree when at least one move is found to be worse than a previously examined move; such moves need not be evaluated further. I call alpha-beta pruning an algorithm because when applied to a standard minimax tree, it returns the same move as minimax would, but prunes away branches that cannot possibly influence the final decision.

5. Ignoring quiescent search and extensions (which continue expansion of the subtree for a particular move if a response is either literally forced (such as a response to a check) or practically forced (if a recapture is needed to avoid overwhelming material disadvantage), continue to expand the tree until all the most promising moves have been evaluated.

6. Propagate the results upwards to the original root of the tree by selecting the move that, at each level, results in the alternating best (maximum) and worst (minimum) evaluation along each branch of the root tree (hence the name minimax). The intent is to select the branch of the search tree (the Principal Variation) that contains the best moves for each player at each level of the root tree. This assumes that each player will, in turn, select the move that results in the most advantageous position for them.

7. Repeat the process by increasing the depth of the search tree by one ply for the best moves (typically a small number, in the order of 5 or so) selected at each ply until the time management function of the chess engine indicates that it's time to make a move.

Premium Chessgames Member
  AylerKupp: Part 2 of 3 <MCTS (and it's close relative, PUCT)>:

1. Start with the current game position and identify all legal candidate next moves.

2. Select the "most promising" candidate next moves based on the training of its neural network.

3. "Evaluate" the resulting position by conducting a series of game simulations (playouts) until a result (win, draw, loss) and determine the scoring percentage (no. of wins + number of losses/2) of that move as well as other statistics such as number of wins, probability that the move being examined will be selected (based on the training of its neural network).

At least that's the traditional definition of MCTS. The "A general reinforcement training ...", the "Mastering Shogi by Self Play ..." articles indicate that they obtain the game result probabilities by doing playouts, the "Technical Explanation of Leela Chess Zero" article indicates that AlphaZero (as well as Leela Chess Zero) uses the PUCT algorithm, and "Game Changer" explains the process reasonably well but never actually says that it uses MCTS and is not clear how the game result probabilities are obtained, other than "the percentage represents the prior move probability" without saying how that's calculated. Then again the focus of the book is to provide examples of AlphaZero's play and not to fully describe how AlphaZero works. But all articles and the book basically refer to an MCTS-time tree generation and branch evaluation and selection.

To make matters worse, MCTS-Minimax hybrids have been developed (see "MCTS-Minimax Hybrids with State Evaluations" and "MCTS-Minimax Hybrids with State Evaluations (Extended Abstract"; you must Google them and download them directly) which, of course, claims that combining the two methods yields the best results, at least in some domains. And, also of course, there seems to be some controversy on the suitability of "pure" MCTS for chess applications (see

4. Expand the tree by repeating the process until a position is found that has not been found and evaluated (examined) before, or a position that ends the game.

6. Propagate the results upwards to the original root of the tree and recalculating the scoring percentage and the other statistics for each branch of the tree.

7. Repeat the process by increasing the depth of the subtree of the move being examined by one ply for those moves in the search tree (again, probably a small number, but I don't know the range of that number) that have the highest expected scoring percentage. Again, the engine's time management function of the chess engine determines when it's time to make a move.

Premium Chessgames Member
  AylerKupp: Part 3 of 3 <Pros and Cons of each>:

Whenever you have 2 approaches you typically have pros and cons for each. In anticipation of your possible next question, here are some pros and cons to either the classic or MCTS-based approaches to tree searching. Most of these pros/cons are from published literature, some are my opinions and observations. The latter may not interest you. :-)

1. Some claim, as stated above, that MCTS is not that well suited for chess applications, contrary to the views of the DeepMind team and Matthew Sadler.

2. MCTS is supposed to provide a "more human" approach as far as best move selection because it immediately narrows down the best move candidates to consider and reduces these to a small number, just like a GM might do. Mathew Sadler says that "An engine such as Stockfish works on the basis that the evaluation of the best move determines the evaluation of the position" which is horrendously incorrect. Classis chess engines work on the basis that the evaluation of the best <branch> (in the minimax sense) determines the best of the move candidates considered. How to determine the best of the move candidates in a classic chess engine is determined by the search heuristics.

3. Minimax will provide the best answer in terms of what moves to play in a zero-sum game, MCTS will only approximate the best answer. But that apparently is good enough, at least under the conditions under which engine vs. engine chess games are played.

4. (my opinion) A classic chess engine using minimax will always be faced with the horizon effect no mater how deep it searches (see a tongue-in-cheek description of "AylerKupp's corollary to Murphy's Law (AKC2ML) in my header above). Based on the example in "Game Changer" MCTS <seems> to be able to reach deeper search depths in the same amount of time than a classic engine because it is apparently more efficient in identifying the best candidate moves and so it can better control the width of its search tree, narrowing the number of branches it needs to consider in order to dedicate its resources analyzing the most promising moves to get good results. It's unfortunate that I haven't been able to find any sources that list the calculation time and search depths achieved by AlphaZero for each move.

But, like Stockfish's aggressive search tree pruning, this is double edged. Yes, the engine can search deeper but it is also more likely to miss the best moves by both sides. Sadler says that "I think this also explains how AlphaZero might occasionally miss an unusual, 'unfair' tactic in a position. Since AlphaZero is pruning possibilities to consider so early and rigorously, it might discount a non-standard move before it could examine it at the depth required to see its hidden strengths.

5.(my opinion) But perhaps the best indication of the relative merits of minimax with heuristics and alpha-beta pruning vs. MCTS is provided by Komodo 12.x. In addition to its standard classic version, it provides an option to use MCTS instead of minimax, etc. and both engine versions have competed in the TCEC, CCRL, and CEGT engine vs. engine tournaments. In all cases Komodo 12.x standard performed better than the corresponding Komodo 12.x MCTS and achieved higher ratings. But, in fairness, the Komodo 12.x MCTS option is relatively new, likely does not perform as efficiently as the standard version (which has been available for some time in Komodo multicore) and even crashed 3 times in the most recent TCEC tournament. So we might not yet be comparing apples to apples in terms of performance, and the CCRL ratings for Komodo 12.x MCTS version have been increasing faster than the Komodo 12.x standard version. But, when all engine components are basically the same, Komodo 12.x with minimax consistently outperforms Komodo 12.x with MCTS.

Hopefully the above answers at least some of your questions. As usual, there is a lot of information out there in case you want to dig deeper.

Premium Chessgames Member
  AylerKupp: <<MrMelad> Regarding our discussion in the AlphaZero page I think it has reached a point where both of us made our best case and we should either wait for others to chip in or just let it be.>

I agree, but there are still some things I want to say to clear up some misconceptions based on your last series of posts and offer yet another example of what I've been trying to say.

<<MrMelad> I'm trying to offset some of your claims as they seem to focus around diminishing and discrediting the accomplishments of AlphaZero and Leela.>

I am in <NO WAY> trying to discredit the accomplishments of AlphaZero and Leela Chess Zero. I think (and have said) that AlphaZero deserves a huge amount of credit for their ability to generalize the implementation of neural network-based game playing engines by reducing the amount of domain specific (i.e. game rules) needed to implement the engine. And Leela Chess Zero showed how neural network based training could be implemented by distributing the task across a network and tapping on the resources of individuals connected to that network. Similar, in a way, how the available computer resources of many individuals were tapped to support SETI.

But I am trying to put things in perspective and correct some of the claims made by the more enthusiastic and apparently ignorant posters out there. First, there is <nothing> original in the algorithms used in AlphaZero; not the use of neural networks for chess playing, the use of reinforcement training of the neural network, or use of MCTS. All of these algorithms have been applied to chess playing before. I'm sure that the AlphaZero developers implemented many enhancements and improvements in these algorithms. But original, no.

What I do think that AlphaZero accomplished is the best <integration> of these algorithms into a chess playing <system> (hardware + software), and as someone who has been responsible for system integration on many projects I know and appreciate how hard and unpredictable this can be. That and the pioneering work of efficiently using TPUs and their massive computational performance advantage to implement the best chess playing <system>.

Premium Chessgames Member
  AylerKupp: <<MrMelad> You use those arguments to "warn" people from giving too much credit to AlphaZero as if the competition between stockfish and AlphaZero was between two similar algorithms that one simply had a huge computational advantage.>

Well, I am trying to make people aware that the results of the AlphaZero and Stockfish matches are inconclusive at best <IF> what you are trying to find out what's the best approach and algorithms to implement the best chess playing engines. Whether the competition was with similar or dissimilar algorithms is besides the point, as long as the two engines are running on hardware with similar computational performance capability, regardless of hardware architectures. If that constitutes a "warning", then so be it.

Let me try a different approach to try to convince you of that. Suppose there a 100-game match was held between AlphaZero and Leela Chess Zero, both of which have similar (though not identical) algorithms and architectures and, of course, likely different implementations of those algorithms. If AlphaZero was restricted to use only one 1st generation TPU (performance estimated at ~30 TFlops) and Leela Chess Zero used a GPU server configuration with two nVIDEA RTX 2080i GPUs, (performance estimated at ~13.7 TFlops each, with an aggregate performance estimated at ~27.4 TFlops) then I would say that the performance capability of their hardware was similar. If results of the match were a near tie (like the previous TCEC's Leela Chess Zero vs. Stockfish Superfinal, even though Leela Chess Zero had a substantial computing capability over Stockfish), then I would conclude that the performance of the algorithms in AlphaZero and Leela Chess Zero was also approximately equal. I think that you would probably agree.

Now conduct another 100-match except allow AlphaZero to use four 3rd generation TPUs, each with a performance estimated at ~ 360 TFlops for an aggregate performance capability of ~1,440 TFlops and a performance computational advantage of ~ 52.5X over Leela Chess Zero. If the first match with hardware of comparable performance capability ended in a near-tie, do you have any doubts as to which engine would win the second match? And if the winner was AlphaZero by a substantial margin (of which I have no doubt), would you then conclude that the AlphaZero <algorithms> were substantially better than Leela Chess Zero's <algorithms>? I hope not. And, if you were to agree that the results of this second match were inconclusive because of AlphaZero's substantial computational capability, would you also have agreed if the first match with two approximately equal hardware in terms of computational performance capability had not taken place?

So yes, I "warn" people against giving too much credit to AlphaZero as a result of its matches against Stockfish when AlphaZero enjoyed a substantial computational performance advantage. Particularly since both DeepMind's data and Leela Chess Zero's experience with a shorter time/move (AlphaZero) and without GPU support (Leela Chess Zero) show that Stockfish, as well as many other classic engines, would defeat them both convincingly if their computational capabilities were similar.

Premium Chessgames Member
  AylerKupp: <<MrMelad> <I don't think your intentions are malicious though, I just don't think you understand how AlphaZero works, i.e., how reinforcement learning or deep learning works.>

My intentions are certainly not malicious, at least not intentionally. I present my opinions and provide data or links to data to support them. What else can I do? If others disagree with my opinions even though they agree on the data presented, or if they choose to ignore the data, there's nothing I can do about that.

As far as not understanding how Alpha Zero, reinforcement learning, or deep learning works, I might surprise you. I have read every paper on Alpha Zero, Leela Chess Zero, neural networks, reinforcement learning, and deep learning that I have been able to find and read, and I have bought two books on neural network design and deep learning that I am now studying. An expert on those subjects? Clearly not, and I have a long way to go to even be considered "knowledgeable". But understanding? I think that I have a high-level understanding, enough I think to filter bs and wishful thinking from facts.

<<MrMelad> <I know sarcasm doesn't always translate well on the internet but I sometimes forget. My apologies for using it, it's not that funny anyways.>

Well, I have the same problem and I try to avoid it but, as you know, it's easy to backslide. And quips that somehow seem funny at the time that I write and post them typically don't seem so funny after a time and after others read them. My post was not intended as a criticism of using sarcasm but just a statement of fact that, unless the use of sarcasm if very, very obvious, it's not an effective way to try to get a point across.

<<MrMelad> Here is the part where he says "You can't really compare CPU cores to GPU cores apples to apples">

What he actually said starting at ~ 00:07:00 was that CPUs and GPUs can't be compared because "they are <qualitatively different>" and the much larger number of available cores in the GPUs means that they can effectively perform a larger number of more limited operations in parallel (no surprise here!). So <CPU cores> cannot be compared to <GPU cores> <because of the kind of things that they can each do most effectively>. That's where the "apples to apples" comment was addressing, not in the context that their computational capabilities can't be compared.

Apr-17-19  MrMelad: <AylerKupp> thanks for you comments. I responded in the AlphaZero page.
Premium Chessgames Member
  diceman: <AylerKupp:

7. Repeat the process by increasing the depth of the subtree of the move being examined by one ply for those moves in the search tree (again, probably a small number, but I don't know the range of that number) that have the highest expected scoring percentage. Again, the engine's time management function of the chess engine determines when it's time to make a move.>

If given enough time, will all moves be looked at? (at whatever the listed ply depth is)

May-20-19  LoveThatJoker: <AylerKupp> Thanks for the engine analysis on 37. Qh8+. I too had gone with this continuation. LTJ
May-20-19  LoveThatJoker: PS. In regards to yesterday's Gazza puzzle.
Premium Chessgames Member
  Sally Simpson: ***

Hi AylerKupp (finally spelling your name correct instead of AlyerKupp)

You will be interested in this:

it's paper on ICAT and chess computers.


Premium Chessgames Member
  AylerKupp: <Sally Simpson> Thanks for the article on iCAT. At first glance I thought that the result should be obvious that chess players would enjoy a game against a physical opponent more than against a virtual opponent but even so it's good to have some confirmation. As you know I am a wine aficionado and I read that some enologists subjected Cabernet Sauvignon grapes to DNA testing to try to find out the grape's origin. After some analysis, at presumably a non-trivial expense, they determined that the Cabernet Sauvignon grape was the result of a cross between the Cabernet Franc grape and the Sauvignon Blanc grape. Then someone pointed out that, given the name Cabernet Sauvignon, shouldn't the answer have been obvious? Particularly since Cabernet Sauvignon, Cabernet Franc, and Sauvignon Blanc are all grown in the Bordeaux region of France.

But I do wonder if the test was too simplistic. I don't know whether the effect of the novelty factor of playing against a physical opponent was properly considered. The article didn't say (I don't think) the number of games that each participant played against the iCat. Could it be that, particularly with the 8 to 12 year old participants, the players enjoyed the game more when faced with the novelty of playing against a physical iCat rather than a virtual one? Would the results have been the same if the same group of players had played a greater number of games against each type of opponent so that the novelty factor would have worn off?

And I don't see why the participants were restricted to one kind of scenario (physical or virtual). It would seem to me that if they had a relatively large number of positions and if these positions were chosen at random, then there would have been minimum chances of duplication. Or, if by chance the same position was selected, a different position would have been substituted for it. And if the participants played both types of opponent (physical and virtual) and the order in which they played each opponent was randomly selected, then a more direct preference comparison would have been achieved. Oh well, just some thoughts.

Premium Chessgames Member
  AylerKupp: <My Experience with Dress Codes>

On my last job before my retirement I was the manager of the software department for a company. The company did have a dress code but it was never enforced or even mentioned and, software developers being what they are, my subordinates pretty much dressed as they pleased, and I never talked to them about it because, frankly, I didn't know what the company's dress code was. I did mention to them, in case they didn't think of it on their own, that if they were giving a presentation in front of our customers, they should dress appropriately, business casual as a minimum.

I personally wore casual attire except when giving presentations to our customers when I always wore a business suits. I never wore jeans except on weekends, and no shorts or sandals or flip flops.

Then one day everyone in the company received an email that the company's dress code will henceforth be enforced. It prohibited everyone from wearing shorts, jeans (even nice ones), and sandals and for the women specifically it prohibited wearing Capri pants, spaghetti straps, and outfits with bare midriffs.

Nobody knew why this email came out of the blue and one of my employees objected particularly strenuously. She said that she was a single mother, her wardrobe consisted only of jeans, and that she could not afford to get a completely new wardrobe. She finished by saying "I'm not giving up my jeans!"

My response was along the lines of "I agree with you. I'm not giving up my jeans, my Capri pants, or my spaghetti straps but by popular request I have agreed to give up my bare midriff outfits."

I of course talked to the powers-that-be to find out what triggered the email. I was told that there were some foreign potential customers visiting the company from a country where they could be offended by our employee's casual dress (and in the case of software developers <very> casual dress) and they didn't want that to happen.

I asked why this wasn't indicated in the email since it did not seem like an unreasonable request for these customer's visits and any other customer's visits from countries that might be offended by our overly casual attire, and that if notified of such visits no one would object to more relatively "formal" attire when these customers were touring our facility, and then revert to their usual attire when there were no customers on site. I was told that this would be very hard to do.

Which was absolute nonsense since <every> visitor had to indicate when they would be visiting our facility and submit their security clearances ahead of time. I always received a notice of such visits and asked my subordinates that they should straighten up their offices and the walk spaces somewhat (software developers tend to be rather messy) prior to the customers' arrival. Which told me that the powers-that-be were not that serious about the "problem" and that the issue would quickly die out. And, sure enough, it did.

Premium Chessgames Member
  AylerKupp: <My Experience with Company Rules and Regulations>

Since I'm on a roll and this is my forum I can address any subject at all (within reason) so I will. This was the incident that taught me that all rules have a way around them and, rather than try to fight an unreasonable (at least to me) rule head-on, it's easier to try to find the loopholes in the rules (there are always some) and go around them.

Many years ago before the existence of personal computers we used minicomputers which could be shared by multiple users. At another company where I was the head of software development for my department we had a centralized minicomputer in the second floor which served the needs of the software developers. Three of my subordinates were sharing an office on the first floor and they had to go upstairs to use the computer. They asked me if I could arrange to have a dumb terminal (the only ones available at the time) installed in their office since that would save them the time to up and down the stairs, increase productivity, blah, blah, blah.

That seemed like a reasonable request to me so I went to talk to the facilities manager. He told me that it was against company policy to do that because in those days they were required to install a hard conduit for the cables leading from the minicomputer to individual offices and, if my subordinates were to move, they would have wasted the money.

I was about to object when I saw the smile on the face of the facilities manager who said "However, if you install two terminals instead of just one, that would make it a terminal room that's OK as far as company policy goes and I will approve the request."

So my subordinates got two terminals in their office instead of one and were even happier. Perhaps FIDE could learn something from my experience.

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