| Mar-26-09 | | mjk: <Nalimov> would win: 61...♘e4 win in 43, or 61...♘e5 win in 61, or 61...♘f5 win in 63. All other moves draw. |
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Mar-26-09
 | | alexmagnus: According to the TB, Anand's had a win in that ending on several occasions, last time on move 70.
click for larger viewHere 70...Nb8 is mate in 41 and 70...Nc6 - mate in 61. |
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| Mar-26-09 | | digitbo: earlier in the game Wang Yue did ok as he followed rybka3 recommendations until 21.Rhe1? rybka recommended 21. Be5 as +1 for White
After that you can tell there is still a large gap in strength between Wang Yue and Anand. |
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| Mar-26-09 | | Eyal: Position after 57.Kc4:
click for larger viewBefore the obscure tablebase wins in the two-knights-vs-pawn ending, Anand's real miss was 57...Nf4! (instad of ...Ne5+?) when Black can win White's c-pawn while keeping his b- and g-pawns with 58.Kb4 Nd5+. |
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| Mar-27-09 | | znprdx: <Aug-08-08 dumbgai: We might not see this endgame occur again at the super-GM level, but if it does it should be interesting to see how the players handle it.> WOW - spooo-ky re Topalov vs Karpov, 2000 |
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| Mar-27-09 | | Eyal: <Anand reached the infamous "Halley's Comet" endgame against Wang Yue in the blindfold. The defunct American magazine Inside Chess had an article on two knights versus pawn and gave it that name because you should only see it once in your lifetime.> (http://www.chessninja.com/dailydirt...) Topalov, btw, happened to play this endgame twice in the same year, though once as the attacker (where he managed to win) and once as the defender (where he managed to draw): Topalov vs Karpov, 2000
Topalov vs Sasikiran, 2000
Not including this one, the endgame explorer features 31 games that reached this endgame: http://www.chessgames.com/perl/ches... |
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| Mar-27-09 | | percyblakeney: Sasikiran played on for twenty moves after taking Topalov's pawn in the above mentioned Topalov vs Sasikiran, 2000, and that even though it was classical time controls, that's being optimistic :-) |
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| Mar-27-09 | | Eyal: <As GM Erwin l'Ami explained to me, the biggest mistake was not to go for 61...Ne4-c5, because the basic idea is to block the pawn with a knight as soon as possible, not with the king. After that a win in 62 moves isn't relevant of course, but 70...Nb8! was the last practical chance. In a way 70...Nb6? is the wrong idea because the White king should be driven to a1, not to a8, where the c-pawn only gets in the way of the mating constructions, as was shown in the game.> (http://www.chessvibes.com/reports/l...) |
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| Mar-27-09 | | firebyrd: <After that [ 21.Rhe1?] you can tell there is still a large gap in strength between Wang Yue and Anand.> At that time there was also a large gap in time remaining. Anand's complications had caused Wang to spend almost all of his time, while the champ had most of his remaining, and seemed to be running the game the way he wanted. Good work from Wang in saving the draw. |
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| Jul-23-09 | | David2009: This NN vs P ending is not as difficult as its reputation. The ending starts at
click for larger view
With perfect play there is mate in 43 (Nalimov). With imperfect play against the program KCHESS (1997 edition, for Windows 95, runs under Windows XP) the game might end
[K-Chess Game]
[BLACK to Play]
[Board]
WP C3; BN F3; BN G3; WK A5; BK C6
[Moves]
1 Ng3-e4 2 Ka5-b4 Ne4-c5 3 Kb4-c4 Kc6-d6
4 Kc4-b4 Kd6-d5 5 c3-c4+ Kd5-d4 6 Kb4-b5 Nf3-e5
7 Kb5-b4 Ne5-d7 8 Kb4-b5 Kd4-c3 9 Kb5-c6 Kc3-b4
10 Kc6-c7 Kb4-a5 11 Kc7-c6 Ka5-a6 12 Kc6-c7 Nd7-e5
13 Kc7-d6 Ne5-d3 14 Kd6-c6 Ka6-a7 15 Kc6-d5 Ka7-b7
16 Kd5-d4 Kb7-c6 17 Kd4-c3 Kc6-d6 18 Kc3-d4 Kd6-e6
19 Kd4-e3 Ke6-e5 20 Ke3-f3 Nd3-b4 21 Kf3-e2 Ke5-e4
22 Ke2-d2 Ke4-f3 23 Kd2-c3 Nb4-c6 24 Kc3-d2 Kf3-f2
25 Kd2-c2 Kf2-e2 26 Kc2-c1 Nc6-d4 27 Kc1-b2 Ke2-d2
28 Kb2-b1 Nd4-e2 29 Kb1-b2 Ne2-c1 30 Kb2-b1 Nc1-d3
31 Kb1-a2 Kd2-c3 32 Ka2-a3 Nd3-b2 33 Ka3-a2 Nb2-d3
34 Ka2-a3 Kc3-c2 35 Ka3-a2 Nd3-b4+ 36 Ka2-a3 Nb4-c6
37 Ka3-a2 Nc5-a4 38 Ka2-a3 Na4-c3 39 c4-c5 Nc3-b5+
40 Ka3-a4 Nb5-c7 41 Ka4-a3 Kc2-c3 42 Ka3-a4 Kc3-c4
43 Ka4-a3 Nc7-b5+ 44 Ka3-b2 Kc4-d3 45 Kb2-c1 Nb5-d4
46 Kc1-d1 Nd4-c2 47 Kd1-c1 Nc2-e3 48 Kc1-b2 Kd3-c4
49 Kb2-c1 Kc4-c3 50 Kc1-b1 Ne3-d1 51 Kb1-a1 Nd1-b2
52 Ka1-a2 Nb2-c4 53 Ka2-b1 Kc3-d2 54 Kb1-a2 Kd2-c2
55 Ka2-a1 Nc6-d4 56 Ka1-a2 Nd4-b3 57 c5-c6 Nb3-c1+
58 Ka2-a1 Nc4-a5 59 c6-c7 Na5-b3 checkmate
[EndGame]
White's time 7 min 20 s Black's time 10 min 9 s (computer playing White matches user's time). I was playing Black and had a long think at around move 33 since the thematic Nc4 is impossible (c4 is occupied by the WP). I also became worried about the looming 50 move draw, hence had to allow the P advance. I am sure that there are better plans for both sides: the point is, the ending is winnable. KCHESS is an old program, but plays reasonably well. When I bought KCHESS circa 1998, I used to win comfortably playing the Windows 3.1 version. When I upgraded to Windows 98 so using KCHESS for Windows 95, the tables were turned. White's play and Black's play are far from optimal: the point is, the ending can be won without expending enormous thought by the player with the NN (one simply looks for patterns/ positions which drive the defending K back). It is noteworthy that in Topalov vs Karpov, 2000 Topalov won at fast-chess time limits: his moves were almost automatic (as were mine in the ending above up to move 32). Karpov lost partly through ignorance (he should have moved his K towards the blockading N and P) partly through bad luck (without time to calculate his 'instinctive' moves turned out to be bad). I am sure Anand would have won without difficulty in normal chess: the double handicap of blindfold plus fast play shows that even world champions are human. This ending, of NN versus blockaded Bishop's pawn was won very efficiently by Seitz in 1931, see Znosko-Borovsky vs J A Seitz, 1931 For useful general comments on this ending (blockaded RP as example) see Game Collection: Two Knights versus Pawn by <Resignation Trap>. Apologies for the length of this post! |
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| Jan-07-17 | | YouRang: This was the position after 61.Kxa5
click for larger view
Since the correct technique requires the opposing pawn to be blocked by a *knight*, his best move was 61...Ne4, so that 62.c4 could be answered by 62...Nc5. Anand, misplayed it with <61...Kc5? 62.c4!> which has the *king* blocking the pawn, and the pawn is far enough advanced that black cannot correct it (e.g. by putting a N on c6) -- IF white plays his side correctly. As it turned out, Yue also misplayed his side giving Anand another chance. After 62...Ne4:
click for larger view
White had the choice of putting his king on a4 or a6. Somehow, <63.Ka4> feels right, but 64.Ka6! was correct, because he can threaten to support his advancing c-pawn, and when the pawn gets to c5, it interferes with black's maneuverability since the pawn cannot be captured! Anand still couldn't find the right technique, and Yue managed to draw at move 85 (stalemate). A very difficult ending for both sides. |
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Kibitzing
