|
< Earlier Kibitzing · PAGE 3 OF 3 ·
Later Kibitzing> |
Jul-13-08
 | | al wazir: And then there's this line: 46. h6 Kh7 47. Nd7 Nd2 48. Nf6+ Kh8 49. Nd6 Nf3+ 50. Kf4, followed by 51. Nxf7#. The draw was so easy to find that I knew there had to be a win. I spent an hour looking for it, without success. I wonder how many GMs could come up with the answer with their clocks running. |
|
| Jul-13-08 | | 4tmac: <LIFE Master AJ> link & <patzer2> #2---anyway, 46. K-h6! K-g8 47. N-d7! N-d4 48. N-e7+ (NxN in real life!!) K-h8 49. N-e5 N-f5+ 50.NxN f6 51. K-g6! PxN 52. h6 a2 53. N-d6! a1=Q 
click for larger view WHITE MATES IN 5! (54.Nf7+ Kg8 55.h7+ Kf8 56.h8=Q+ Ke7 57.Qd8+ Ke6 58.Ng5#) |
|
| Jul-13-08 | | whiteshark: <46.Kh6 a2 47.Ne7 a1=Q 48.Nf7#>. I'm sure there are some better defences. :D |
|
| Jul-13-08 | | 4tmac: In fact, that's why angelfire calls 46. K-h6! <K-g8?!> a slight error because it is now "mate in 12" beginning with N-d7!. In fact, it may be mate in 13 (or 14 or 15) from the "initial position" (move 46) |
|
| Jul-13-08 | | avidfan: Instinct led me to the best move 46.Kh6 as hinted by the puzzle's title <What is White's best move?> after realizing that chasing and capturing the a3 pawn would be useless with possible mating chances - considering the liability of the Black f7 pawn helping to corral the Black king. |
|
| Jul-13-08 | | 234: Saturday puzzle Jul-12-08 <44. ?> Gelfand vs K Lerner, 1987 |
|
| Jul-13-08 | | avidfan: Even in the mate in 5 by <4tmac>, the pawn proves to be a liability, depriving the Black king of a flight square - another good example of cooperation by queen and knight.
click for larger view |
|
| Jul-13-08 | | patzer2: <4tmac> That's an amusing mate-in-five! Thanks for sharing it. In addition to <4tmac>'s interesting mate, there are several simpler possibilities after 46. Kh6!! where White can ignore the passed a-pawn, allow Black to promote and still pull off a quick mate. Reviewing a few of these might help in understanding today's puzzle. Here's three of them as puzzles: (1) Solve for mate-in-two after 46. Kh6!! a2 (diagram below): 
click for larger view(2) Solve for mate-in-three after 46. Kh6!! Kg8 47. Nd7 a2 (diagram below): 
click for larger view(3) Solve for mate-in-three after 46. Kh6!! Kg8 47. Nd7 f6 48. Kg6 a2 (diagram below). 
click for larger viewSolutions:
(1) 47. Ne7 a1=Q 48. Nxf7#.
(2) 48. Ne7+ Kh8 49. Ne5 a1=Q 50. Nxf7#.
(3) 49. Nh6+ Kh8 50. Nxf6 a1=Q 51. Nf7#. |
|
| Jul-13-08 | | johnlspouge: Sunday (Insane): What is White's best move?
Material: Endgame 2N+P vs. N+3P. Both sides have passed Ps. The White Nf5 can catch the Black Ph6 with Nf5-e3-c7, but on its own, the sacrifice of Nf5 for Ph6 leaves White down a P, with no immediate prospects of h8=Q. White therefore needs to focus on forcing h8=Q. In present form, his problem is to clear the stop squares h7 (and h8) before a1=Q. The Ne5 is likely to control h8; Kg5, h7. The Nf5 therefore requires activation. Without calculation, the obvious candidate 46.Nxf7+ looks insufficient; calculation shows that 46.Ng6+ draws. Candidates (46.): Ng6+, Kh6
46.Ng6+ fxg6 47.hxg6 a2 48.Kh6 [Kf6 a1=Q+] a1=Q
49.g7+ Kg8 48.Ne7+ Kf7 49.g8=Q+ Kxe7
with a draw. To accelerate promotion, however, White has a mate threat. 46.Kh6 (threatening 47.Ne7 48.Nxf7#)
The mate threat gives White undisputed control of the stop square h7. (1) Black can counterattack:
46…f6 47.Nf7+ Kg8 48.Kg6 (threatening 49.h6 50.h7+ 51.h8=Q#) To avoid mate, Black must flee. (Transpositions can occur but the essential line follows.) 48…Kf8 49.h6 Ke8 50.h7 a2 51.h8=Q+ Kd7
52.Qd8+ K moves 53.Nd4+ Nxd4 [else 54.Nxb3] 54.Qxd4
and White wins.
(2) Black can frustrate the threat directly:
46…Kg8 47.Nd7 (threatening
48.Ne7+ then 49.Ne5 50.Nf7# or 49.Nf8 50.Ng6#)
47…f6 48.Kg6 a2 49.Nh6+ Kh8 50.Nxf6 a8=Q 51.Nf7# |
|
| Jul-13-08 | | johnlspouge: <<al wazir> wrote: I wonder how many GMs could come up with the answer with their clocks running.> In addition to hanging around http://chess.emrald.net/ to improve my speed, I am now timing myself. I <never> use a board before posting, and I took 1 hour to write my post today (including its explanations). |
|
| Jul-13-08 | | Helios727: 46. h6 a2; 47. Ne7 a1=Q; 48. Nxf7+ Kh7; and there is no win for white. 46. Kh6 f6; 47. Nf7+ Kg8; 48. Kg6 Kf8; 49. h6 a2; 50. h7 Ke8; 51. h8=Q Kd7; 52. Qd8+ Kc6; 53. Qd6+ Kb5; 54. Nd4+ (A) 54... Ka4; 55. Qd5 a1=Q; 56. Qb5+ Ka3; 57. Qxb3#
(B) 54... Kc4; 55. Nxb3 Kxb3; 56. Qxd3+ Kb2; 57. Qd2+ Kb1; 58. Qd1+ Kb2; 59. Qd2+ Kb1; 60. Qb4+ Kc1; 61. Qa3+ Kb1; 62. Qb3+ Ka1; 63. Nd6 f5; 64. Nb5 f4; 65. Na3 f3; 66. Nc2# |
|
| Jul-13-08 | | Some call me Tim: Beautiful! I looked at Kh6 as one of the first alternatives as it seems if Black can get his K to h7 he can defend more readily. But I did not find the winning line so went to other moves. This is worthy of a composed problem. |
|
| Jul-13-08 | | johnlspouge: <4tmac>, thanks for that beautiful variation! |
|
| Jul-13-08 | | avidfan: For anyone reading <johnlspouge'>s post, the Ph6 should be correctly read as P<a3> and N-c7 should be N<c2>. It never ceases to amaze me how he gets the solutions to the daily puzzle almost without fail when I can barely get past Friday's generally. I did manage to "assess" today's key move. |
|
| Jul-13-08 | | zooter: Why not just 49...a1=Q? What's the need for the knight move? |
|
| Jul-13-08 | | zooter: Ok, horrible mistake, in the final position a direct 49...a1=Q+ will lead to 50.Kf7 when black has no way to stop a draw by perpetual check with his knight to f8-g6. I also looked at the 50...Qa3 line and it looks like the game might be very evenly poised if black sacrifices his queen for the knight on f8. Any help on this line of thought would be much appreciated |
|
| Jul-13-08 | | Udit Narayan: if zakharov can't find it then where it leaves me? |
|
| Jul-13-08 | | Ingolf: Another hour spent in a way people who don't play chess will never understand, but I got it! 49.Nh6+ (in the second line in the annotation) was the most tricky move to see, but it also took me a while to realise that in the first line, the pawn on f6 blocks the diagonal allowing the h-pawn to promote without being exchanged. |
|
| Jul-13-08 | | johnlspouge: <<avidfan> wrote: For anyone reading <johnlspouge'>s post, the Ph6 should be correctly read as P<a3> and N-c7 should be N<c2>.> Thanks, <avidfan>. I am keeping a Word document of my solutions, so I greatly appreciate your corrections to my typos. <It never ceases to amaze me how he gets the solutions to the daily puzzle almost without fail when I can barely get past Friday's generally.> ...and it never ceases to amaze me how my notation keeps mirroring the chessboard, despite all efforts to the contrary. I am the ultimate chess dyslexic. More seriously, about 8 months ago, when I started visiting this site, I could not solve past Wed-Thu, but at the beginning of anything, everyone understands nothing. The secret of my success here (if and when it occurs) is to learn methodically and to apply the principles in "How to Solve It" by George Polya (my favorite modern mathematician) to solving the chess puzzles. Polya gives four steps to solving a mathematical problem: (1) get the elements into your head; (2) form a plan; (3) check that the plan works; and (4) reflect on what made the solution work. The difficulty really lies in Step 2, but the other steps are immediately accessible. My posts clearly reflect Step 1 (which enumerates geometric relations of the pieces for pins and skewers, the escape squares for the opposing K, passed Ps, etc.). Step 3 is the calculation of variations that many people seem to loathe, but which is absolutely essential for exposing key moves that look good but do not work (Ng6+ for me today). Step 4 is where everyone else's posts come into play for me: we all think so wonderfully differently. I particularly enjoy <dzechiel> for his obvious experience and domain-specific knowledge, <YouRang> for his insightful logic, and <patzer2> for patient synthesis of variations. You never know, however, who is going have a critical insight - I was unaware of <4tmac> before today. Step 4 (review of the solution and how you missed it) is probably the most important problem-solving process, but most people overlook it - nobody really enjoys his own failures. Never be amazed by what someone knows: you can always learn at least some of it. |
|
| Jul-13-08 | | DarthStapler: I didn't get it |
|
| Jul-13-08 | | Magic Castle: After calculating that white will lose the pawn race to the 8th rank, I look for a mating comkbination and after a long look saw the key move Kh6 to prevent the pawn check sacrifice, and Nd6 to cut off the black king's escape. So the rest looks elementary. It is just a question of maneuvering the other Knight for the kill. Of course if black pushes the f pawn to create an escape space, white simply occupies g6 to frustrate it. The urgency of the situation makes this puzzle not as hard as it appear. |
|
| Jul-13-08 | | TheaN: 6/7
"TheaN you knew it, TheaN you knew it, TheaN you knew it...*walks away from the Sunday puzzle bashing himself*" DAMN. I knew anything else did not win, actually loses besides Ne3 (which should've been White's alternative to Ne7?? to at least draw the game). I saw Kh6! but both Kg8 (missing that Kg6 would've allowed the a1 Queen to spot h8, but not the mate) and f6 (missing that Nf7+ at that point does NOT remove the mate threat due to the same Kg6) stumped me, and I gave up. A hard conclusion to a rather easy week... well, I faired pretty well. |
|
| Jul-13-08 | | TheaN: Actually, even my forfeit post shows I did not get it: f6, obviously, breaks the diagonal, and White is free to promote and mate with the Queen... *sigh* if I had seen that I would've continued on Kg8... and probably have made it in the end. |
|
| Jul-13-08 | | jovack: finally.. an endgame puzzle
i wish there were more every week instead of the occasional sunday |
|
| Jul-14-08 | | kevin86: The pawn was a burden to black-so he had to dispose of it. White missed checkmate and has to regret tossing away a brilliant win. |
|
 |
|
|
< Earlier Kibitzing · PAGE 3 OF 3 ·
Later Kibitzing> |
Kibitzing
sac: 22...dxc4
