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Feb-05-05
 | | kevin86: I once heard of a great champion who pulled off a great mating combination. His opponent asked why he didn't announce mate. The champ replied,"I didn't see it!"
Sometimes what we see as great planning is just good plodding. |
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Feb-05-05
 | | patzer2: I also picked 41... xe4!!, but I am reluctant to say I solved it because I did not see all of the subtleties involved:41...xe4!! 42.xf8 (42.Qd4 Qxd4 43.Rxd4 Ng5; 42.Qg3 Rb3 43.Qxh3 Rxe3 44.Qf5+ Qxf5 45.Rxf5 Ra3  ) 42... f2+! 43. xf2 [a) 43.Kg1 Qxe3 44.Rxf7 Ng4+ 45.Kh1 (45.R7f2 Rxf2 46.Rxf2 Qxf2+ 47.Qxf2 Nxf2 ; 45.R1f2 Rb1#) 45...Qe5! 46.Rxg7+ (46.g3 Qh5+ 47.Kg1 Qh2#) 46...Qxg7 47.Qf5+ Kh8 48.Rc1 Nf6 49.Rc8+ Ng8 50.Qe4 Ra2 51.Rc6 b3 52.Rg6 ; b) 43.Kh2 Qh4+ 44.Kg1 Qh1#]
43...h4+ 44. g1 xf2+ 45.h2 f4+ 46.h1 xe3 47.xf7 g3–+ |
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Feb-05-05
| | patzer2: Laura Ross played a great defensive combination in 41...Qe2!! The results are quite amazing, given that none of her pieces are protected and three of them are en prise! This is indeed an amazing display of resourceful counter-attacking defense! If I could suggest one small improvement over the complicated (but still decisive) 43...Nf2+! at the end of the game, it would be to play for a quick and simple mate (mate-in- four) with 43...Nf4+! 44.Kg1 (44.Kg3 Ne2+ 45.Kf2 Qh4+ 46.g3 Qxg3#) 44...Ne2+ 45.Kf2 Qh4+ 46.Kf3 Qg3#. |
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Feb-05-05
| | patzer2: Black played well throughout the game, but White could have had counter chances well into it by avoiding 34.Ne7+? (34.Rc6  ) and 37.Nf5?? (37.Rd3  ). |
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Feb-05-05
| | patzer2: Laura Ross may indeed by an up and comer if this game and http://www.uschess.org/ratings/top5... or http://www.ishipress.com/lauraros.htm are good indicators. |
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| Feb-05-05 | | iron maiden: At 16 and with a 2100 rating, she's probably not the next Judit Polgar, but I think she might have it in her to work on the Irina Krush level, as long as she keeps at the game. |
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| Feb-05-05 | | aw1988: <patzer2> How did Qe2 and Qxe4 end up in the "Defensive Combinations" catagory? |
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Feb-05-05
 | | chessgames.com: Patzer2 is right, this is a defensive combination because at the start of the puzzle Black has a material advantage, but has to cope with the problem of having a Queen, Knight, and Rook simultaenously en prise. |
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| Feb-05-05 | | artemis: <greystar69> I would be flabbergasted if she did not calculate throuhg to the ending. I am currently reading Jacob Aagaard's Excelling at combinational play, where he gives a puzzle which appears to be winning in five moves, as black would have to give up a queen in an otherwise even position to hold off mate, but black finds an excellent drawing resource that forced the game on for seven more moves, where White has forced a massive trade, but has lured his opponent into a Zugzwang in the endgame. Aagaard suggests that a truly strong tactical player should be able to calculate to the Zugzwang from move one without moving the pieces. He admits that someplayers of 2350 rating have difficulty finding the combination in five, so the book is obviously geared towards those who want to be very strong players. I defenitely find it unbelievable that she did not calculate through to the finish, as it would be unlikely that she would play it over the quieter and somewhat less immediate Qxe4. <Patzer2> yes three of her pieces were enprize, but her opponent is only allowed to take one piece a turn. |
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| Feb-05-05 | | aw1988: Very true. Thank you chessgames.com. |
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Feb-05-05
 | | Gypsy: <artemis: ... Aagaard suggests that a truly strong tactical player should be able to calculate to the Zugzwang from move one without moving the pieces. ...> Here it may be helpful to separate notions some. First, it is actually not that difficult to visualize 34 plyes (17 moves), as long as it is fairly easy to find the moves. Some powerful moves are obvious, but many are so counterintutive, that most of us walk right by them even though they can be played in 0- or 1-ply (i.e., right now). Second, it also depends how many pieces actually get into new positions during the whole combo, and, third, how many of those changes are structural. Especially towards the endgame, even long combinations often change the positions of only couple of pieces repeatedly over and over.
Those combinations are much easier to calculate.
And, fourth, combination's difficulty depends mightily on the degree of branching in the combination. It is the number of different positions one needs to visualize that is of essence (not even considering the added book-keeping difficulty of keeping all positions sorted out during the exploration and returns to the higher branching points). Even with average branching factor of only 2, a 5-move combo yields some 1000 position for examination. In contrast, 17-move combination with the average branching factor of 1 yields only 33 or 34 positions. I believe that good measures of combination difficulty need to incorporate: (1) total number of positions you need to look at,
(2) a "distance" of those positions from each other of at least from
the starting position, (3) the total number of forks in the enumeration tree (because of bookeeping difficulties), and (4) total number of distinct moves involved, and (5) a measure of how difficult it is
to discover the moves.
(Of these, (1, 3, and 4) can be readily enumerated; a generalization of
Ulam distance can be used for (2); but I have not thought of any useful quantification for (5) yet.) |
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Feb-05-05
 | | pittpanther: It seems that 42 Qg3 puts up a stiffer defense for white. White is still attacking the f pawn and black has to spend at least one tempo to protect his knight although after 42 ... Ng5 things look bleak for white - but better chances than in the game. |
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| Feb-05-05 | | EXIDE: Another example of a fine ending. |
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| Feb-05-05 | | MoonlitKnight: 40.Qxf8 would also have been pleasing to the eye. 40...Nf2+ 41.Kh2 Ng4+ 42.Kh1 Qh3+ 43.gxh3 44.Rh2# |
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| Feb-05-05 | | WillC21: <Gypsy> You think it's not very difficult at all to visualize 34 ply ahead? Are you insane? I don't think you know what a ply is. A ply is a color's complete move set and all the other color's possible reactions to that move set. Maybe the world's strongest computers under "normal" time controls see this far ahead, but certainly no human! Grandmasters only calculate variations stemming from 3-5 candidate moves, on average! In fact, calculating ply just is not the way any human approaches chess, my friend! |
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Feb-05-05
| | Gypsy: <A ply is a color's complete move set and all the other color's possible reactions to that move set> Your definition is different than my. I took ply as just a half a move in a sequence. |
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Feb-05-05
| | Gypsy: Now it may be a matter of semantics < WillC21>, but this game, for instance, claims to have <PlyCount "96">. From that I extrapolated that ply=1/2 move -- and believe that I also read that at some book I was browsing through. Could you check the definition? It would be great to know for sure. (Btw, I certainly can visualize the entire game like this one and I believe anyone can.) |
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Feb-05-05
 | | tamar: <gypsy> Your description of the conditions necessary to calculate far ahead reminded me of the final 19 moves of Capablanca vs K Treybal, 1929
where by fixing the pawn structure with 39 b6 and having possession of the only file, any player, not just Capablanca could calculate out to move 58.
Alekhine mentions a similar instance in his book. |
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Feb-06-05
| | Gypsy: <tamar> Jup, the Capablanca-Treybal game is a good example. I believe that good tactical ability has two aspects: concentration and alertness. Concentration lets us remember the positions of pieces and visualize the position down, say, 5 or 7 moves later. Alertness lets us discover interesting and important moves. Note that these two naturally work against each other. Most people can stay alert, but have problems of concentrating and submerging into the position, so their vision is often "warped" and inacurate. But, conversely, people with extensive technical training are often too good at concetrating. (I am one of those.) They see fairly easily down those 5-7 moves, but at the same time easily miss that a bishop is free for taking on the move one. Books do not make distinction and always run the mantra of concentration, concentration, concentration. I propose that we are better served when we realize which type of thinking we naturally fall into and then work on improving the complementary skil. (Using myself as an example again, as long as I manage to stay alert, I "see everithing". But habits are hard to break and it is so easy to let yourself be sucked into the game....) |
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| Feb-06-05 | | WillC21: <Gypsy> Ok, a ply is a half-move, as I found by doing some research on my chess program. I stated this wrong, but still 34 ply(17 moves) is not common for a human. Of course a person can setup an extremely simple chess position, due to some unique geometry, where the position can be calculated ahead very far by a fairly strong human chess player. I was more talking on average; like if you take a snapshot from the average middlegame position of grandmaster game they are never exhausting 34 ply worth of possibilites. The method of such exhaustion is a way a computer can play strong chess, but a way in which the human mind would be wasting time and efficiency, since so much of our efforts come by way of intuition. Once again, a very simply geometric position can be setup where massive calculations can be made by a human, but that is not the scenario most humans encounter during their average tournament chess game. |
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Feb-06-05
| | Gypsy: In that case we are on the same page <WillC21>. |
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Feb-06-05
| | patzer2: <aw1988><How did Qe2 and Qxe4 end up in the "Defensive Combinations" catagory?> When I first looked at the position and saw all those enprise pieces, I though to myself how is Black going to get herself out of this mess? Then it came to me that it has to be some kind of defense by counter attack (e.g. desperado move perhaps?). Of course I could have put it under "weakened castled position" or "pursuit (king hunt)," but that doesn't do justice to the astounding defensive role that 41...Qe2!! plays in rescuing this position (that at my first glance appeared lost). Kind of reminds me of those old Western movies where the hero figures out at the last second how to overcome an apparently fatal situation and then make everything right. The wonderful thing about this move is that it not only gets Black out of her predicament, but it also has the nice added bonus of winning. |
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| Feb-06-05 | | aw1988: <patzer2> I recognize that now, my apologies for not spotting it earlier. Topalov-Leko has the same idea; h6!! and Kh7!! *somehow* find a way to win. :P |
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| Feb-22-05 | | artemis: <willc21> have you ever played blind-fold chess? There you have to play the entire game without looking at the board and remember all of the pieces. I have played blind fold games and while they are difficult they are not impossible. I have looked 19 moves ahead in a game before (only to find that my intended move didnt work!!) and I am far from master level. While these variations were in an endgame, it was a rook and bishop (with five or six pawns a side). So while it is easier than a middle game position, it is still 19 moves. In middle games (sicilian middle games at that) I have looked up to 10 moves ahead, although from time to time I miss a line or wrongfully dismiss a move. The point is that even for non-master players, the ability to see far ahead is not a natural ability, but it is an attribute that can be improved over time. |
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| Feb-22-05 | | WillC21: <artemis> I actually have never played blindfold chess. I should though. I agree with you, 10 moves in certain middle games is very possible, even for non-master players. The point I was trying to make was that humans don't tend to evaluate in terms of "ply." In other words, we can see certain lines fairly deep, but we don't examine as many possiblities the way a computer does. This is because we have intuition. It may seem obvious now, but that was my only point. |
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