< Earlier Kibitzing · PAGE 3 OF 3 ·
|Jul-05-07|| ||Caissanist: <I don't see any obvious mistakes for black after the eighth move--perhaps he is already lost by then.>|
It turns out that Crafty disagrees with me. The engine says that 14...O-O (instead of 14...f5?) leaves white with only a small edge. While that's certainly not a position that I would want to play as black, it does seem to be survivable.
|Jul-05-07|| ||PAWNTOEFOUR: well i got the first four moves,then i let shredder show me the rest..but as far as the puzzle goes,there's nothing else to do but go Rxg7+|
|Jul-05-07|| ||Crowaholic: Much easier than yesterday's, which I missed. I actually thought it was too easy for a Thursday and analyzed many lines including declining the sac offer where I basically found|
27. Rxg7+ Kh8 28. Qg3
to be winning for mostly the same reasons that the accepted sac wins. Then I looked at the solution and saw that Geller resigned immediately after Rxg7+... oh, well. I learned something anyway.
<dzechiel: 30 Qxg8+! Nxg8 31 Nf7#>
Hmm, nice Q sac, although the knight sac suffices to deflect the Black knight: 30. Nf7+ Nxf7 31. Qxg8#.
I know, a mate is a mate, but I'm a hopeless perfectionist... :o) More importantly, Black has a better defense than 29. ..Rg8 to which ..Ng4 (which you mentioned) is the key, e.g.
29. ..Ng4 30. hxg4 Qa7! 31. gxf5 Qxg1+ 32. Qxg1 exf5 33. Qd4!
Now White is "only" a minor piece and a pawn up, and the old mate threats no longer work. On the other hand, White is threatening to promote as well as bring in his other knight and finish Black off and this won't take too long. But these moves do manage to delay the mate for a while.
|Jul-05-07|| ||SpecialK: 27. Rxg7+ yields mate in a few moves, nothing more to say.|
|Jul-05-07|| ||MostlyAverageJoe: <Crowaholic: 29. ..Ng4 30. hxg4 Qa7! 31. gxf5 Qxg1+ 32. Qxg1 exf5 33. Qd4!>|
No, Qd4 is too passive.
Hiarcs recommends 33 Nd5! and mate in 9. Here's the entire line (starting from the puzzle position, to make sure I did not misunderstand the moves leading to your line above):
27. Rxg7+ Kxg7 28. Qg3+ Kh8 29. Rg1 Ng4 30. hxg4 Qa7 31. gxf5 Qxg1+ 32. Qxg1 exf5 33. Nd5 Bb7 34. Nf6 Bd5 35. Qg5 Bf7 36. Nxh7 Bg6 37. Qxg6 Rbe8 38. Nf6 Rxf6 39. Qxf6+ Kh7 40. Nxe8 a5 41. Qg7#
|Jul-05-07|| ||patzer2: For today's puzzle solution, it's the demolition sacrifice 27. Rxg7+!! to the rescue.|
|Jul-05-07|| ||Crowaholic: <MostlyAverageJoe: No, Qd4 is too passive.>|
You are right, Nd5 wins more quickly than Qd4.
|Jul-05-07|| ||fm avari viraf: White is having a dream position & all his superior forces are ready to crush. After having a glance, 27.Rxg7+ finishes off Black's feeble defence as 27...Kxg7 28.Qg3+ Kh8 [ even 28...Ng4 won't work ] 29.Rg1 & again Black is hapless.|
|Jul-05-07|| ||xKinGKooLx: As soon as the picture of the board came up on my screen Rxg7 jumped out at me, and after a bit of simple analysis I found out that it works in this position. This puzzle should have been a Monday puzzle in my opinion, because most Monday puzzles are simple sacrifices like this one. A bit unchallenging for a Thursday, but it was a nice simple puzzle that I enjoyed. I'm looking forward to tomorrow's puzzle.|
|Jul-05-07|| ||Fezzik: I don't know why, but these sorts of attacks are really easy for me, even with the Ng4 defensive idea thrown in. |
I guess I must have spent part of my childhood in chess right.
Or perhaps, I wasted my childhood playing chess. Hmm.
Anyway, It's scary that Wednesday and Thursday were both easier for me than Tuesday's was.
(FYI: Regarding my comments on cg.com on July 4th: When I logged on, it was just moments after midnight eastern time, and cg.com had yet to set its banner. I didn't notice whether the game of the day or the variation, quote or other items were changed yet. I always look at the puzzle first. I am glad cg.com did decide to remember the day. Another idea for 7/14: an epic king-hunt!)
|Jul-05-07|| ||MostlyAverageJoe: <Crowaholic> Here's mate in 15 after 33. Qd4 (and after 3 CPU hours :-) |
33. ... Qd4 h6 34. e6+ Kh7 35. e7 Bb7 36. exf8=Q Rxf8 37. Nxb7 Rf7 38. Nd6 Re7 39. Nxf5 Rf7 40. Qe4 d6 41. Nxd6+ Kg7 42. Nxf7 Kxf7 43. Nd5 a5 44. Qe7+ Kg6 45. Qf6+ Kh5 46. Ne3 a4 47. Qf5+ Kh4 48. Qg4#
|Jul-05-07|| ||bogo78: < al wazir: I saw 27. Rxg7+ Kxg7 28. Qg3+ (who didn't?), but I also saw the continuation 28...Ng4 29. hxg4 Rg8 30. gxf5+ Kf8.> How about 31. Qh4 ?! All the variations i have checked lead to white winning shortly but i might be overlooking something.|
|Jul-05-07|| ||TommyC: One for The Times?|
|Jul-05-07|| ||YouRang: It looks like white also had a nifty combo at move 23. (diagram:white to move):
click for larger view
23. Rhg1! Qxh3 24. Nd5! <threat: Qe7+ with mate to follow> Qh4 <guards e7; if 24...exd5, then 25. Qxd5+ & Qxa8 > 25. Nxc4! <threat: 26. Nd6+ Kg8 27. Nf6+ Kf8 28. Nc8+ Kf7 29. Rxd7#>
g6 <make room for king at g7> 26. Rh1 Qd8 27. Nd6+! Kg7 (diagram:white to move)
click for larger view
28. Rxh6! <rook is safe since 28...Kxh6 29. Nf7+, winning the queen>. Now. if black tries to recover material: 28...exf5, then 29. Nxf5+! gxf5 30. Rg1+ Kxh6 31. Qf2! <with mate in 2>.
|Jul-05-07|| ||Crowaholic: <MostlyAverageJoe: Here's mate in 15 after 33. Qd4 (and after 3 CPU hours :-)>|
Well, I saw this mate in 15 at a glance, but missed the mate in 9 starting with Nd5 because of a mental mistake. I'm sorry.
Just kidding... ;-)
<YouRang: It looks like white also had a nifty combo at move 23>
Very interesting, thanks! But isn't this mate in 3 at the end?
31. ..Qe8 32. Qh4+ Qh5 33. Qf6+ Qg6 34. Rh1#
What am I missing?
|Jul-05-07|| ||vortex2639: dang, got to 27. Rxg7 Kxg7 28. Qg3+ Kh8 29. Rg1 and thought Rg8 killed the attack, didn't see the smothered mate.|
|Jul-05-07|| ||YouRang: <Corwaholic><Very interesting, thanks! But isn't this mate in 3 at the end?> You're right. It's very embarrassing that you saw mate in 15 at a glance, and I couldn't even see a mate in 3. ;-)|
|Jul-05-07|| ||Billosky: This is one of the first thursday puzzles I've gotten right away, so all those who complain it doesn't deserve such a late day in the week are probably right. White just has so much firepower one has to look at how to make the R to g7 option work.|
|Jul-06-07|| ||LIFE Master AJ: < <Mostly> "Yeah, counts, but forget about 29.Qg5 ..." > |
Your line did not work out on Fritz 10. After 30 minutes, the metal monster is showing "plus-over-a-line," so 29.Qg5 may win after all.
|Jul-06-07|| ||al wazir: <bogo78: How about 31. Qh4 ?!> I considered it, but I didn't see mate in all variations. However, you're right, it does seem to work.|
|Jul-06-07|| ||LIFE Master AJ: < Jul-05-07 <Caissanist>: This puzzle reminded me of Spielmann's comment that he could find winning tactical shots just as well as Alekhine could, but wasn't as good at reaching positions that had them. Black's position is so cramped and passive that it practically screams "sacrifice leading to mate", and n doubt there are a number of other wins besides Rxg7. I was much more impressed by Grischuk's play leading up to the sac than the sac itself. |
While trying to figure out just where black went wrong, I became suspicious of black's opening. I hadn't seen this line before and it doesn't seem right, leaving the d-pawn backward and the king in the center. Sure enough, opening explorer shows that, after 8.O-O-O, white won 47% of the games in the database, and black only 17%. I don't see any obvious mistakes for black after the eighth move--perhaps he is already lost by then. >
After playing through this game, I felt exactly the way that you did. So I decided to annotate the game. At first I was going to do it in five minutes ... that has turned into nearly two days of analysis.
|Jul-06-07|| ||MostlyAverageJoe: <LIFE Master AJ: < <Mostly> "Yeah, counts, but forget about 29.Qg5 ..." > After 30 minutes, the metal monster is showing "plus-over-a-line," so 29.Qg5 may win after all.>|
The symbolic representation of advantage is not necessarily conclusive, even when it is as strong as (especially in end-game, but also in mid-game).
How many plies deep did you go, and what was the absolute numerical value? What was the beginning of the line?
With Hiarcs 11.1 MP, I am getting only +0.52 at 24 plies deep, which also shows as plus-over-a-line, but really it is a very slight advantage for the white, and most likely a draw. The valuation is decreasing as the analysis progresses (was +0.65 at 20 plies), which is a bad sign for the white's chances. The strongest play for both sides starts thus:
29. Qg5 Qf3 30. Qxh6 Bb7 31. Kb1 Qg2 32. b3
Sliding forward analysis indicates that each move after Qg5 is substantially (>0.5pt) stronger than the next best move for either side. Only after arriving at <32 ...?> there is any doubt regarding the next best move
|Jul-09-07|| ||LIFE Master AJ: http://www.geocities.com/lifemaster...|
|Jul-09-07|| ||LIFE Master AJ: The above is a link to this game ... annotated, with a couple of diagrams.|
|Mar-28-13|| ||Eisenheim: Don't Jakov in the corner. (too crude a pun?)|
< Earlier Kibitzing · PAGE 3 OF 3 ·