g15713: Did Black miss a win in the rook endgame?
E. 1
Rook and four pawns against rook and two pawns.
The critical position is:
Black to move. Last: 56.f4
 click for larger viewDoes Black play 56...gxf4+ exchanging pawns or is it better to play 56...g4 as now the knight pawn is passed and protected? A consensus among the chess users above was that 56...gxf4+ was a mistake and 56...g4! was a winning move. Stockfish 60-minute analysis after 56...g4 agrees: 1) -6.91 (39 ply) 57.Kh4 c4 58.Kg5 Rf8 59.Kh6 c3 60.Kg7 Rc8 61.Re1 Kd4 62.Kf7 c2 63.Re8 Rxe8 64.Kxe8 c1=Q 65.h8=Q+ Ke4 66.Qh2 Kf3 67.Kd7 Qxf4 68.Qh1+ Kf2 69.Qh4+ Ke2 70.Qh8 g3 71.Qg8 Kf2 72.Qa2+ Kf3 73.Qd5+ Qe4 74.Qd1+ Kf4 75.Qxd6+ Kf3 76.Qd1+ Kg2 77.Qd2+ Kh3 78.Qh6+ Qh4 79.Qd2 f4 80.Qc3 Qg4+ 81.Kd6 f3 82.Qa1 g2 After game continuation 56...gxf4+ 57.Kxf4 one has the following: E. 1.1
Rook and three pawns against rook and one pawn
Black to move. Last: 57.Kxf4
 click for larger viewGame continuation:
57...c4 58.Kxf5 c3 59.Rd7
E. 1.2
Black to move. Last: 59.Rd7
 click for larger viewMbourzut wrote an article in Chess Publishing about this ending Reference: 'https://www.chesspub.com/cgi-bin/ch... <"Bogoljubov played 59...Rc8?! and drew after60.Rc7! Rf8+ 61.Kg6 Kd4 62.Kg7 Rb8 63.h8Q Rxh8 64.Kxh8 E. Klein in the Journal de Geneve, 1934 claimed that Black could have won with 59...Rh8!">
E. 1.3
White to move. Last: 59...Rh8
 click for larger view<"This verdict seems to have been accepted by Cheron (his #404), the ECE, and V. Charushin in his monograph on Bogoljubov.Here are some of the variations that were considered: 60.Kf6? Kc6 (60...c2 61.Rc7 Rxh7! also wins) 61.Ke6 c2 62.Rxd6+ Kb5-+ 60.Kg6? Kc6! 61.Rg7 (61.Ra7 d5 62.Rg2 Rxh7 63.Kxh7 c2-+) 61...d5 62.Rg8 Rxh7 63.Kxh7 d4-+ 60.Kf4? This is E. Klein's main line"> See above reference for analysis on 60.Kf4?
E. 1.4
<"The best defense is 60.Rc7! analogous to the game continuation. Then after 60...Kd4 we arrive at">  click for larger view<"Now Klein only considers 61.Ke6? which indeed loses to 61...d5 (Here Cheron claims that after 61...Kd3 White can draw with 62.Rd7, but Black still wins with 62...Ke4!) 62.Rd7 (62.Kd6 Kd3-+) 62...c2 63.Rxd5+ Kc4 64.Rd7 Rc8-+But why not 61.Kg6! similar to the game continuation? After 61...d5 62.Kg7 Rd8 63.h8Q Rxh8 64.Kxh8 Black has indeed gained a tempo compared to the game continuation, but a straightforward analysis shows that is still not enough to win the game. So, the verdict is that Bogoljubov did not miss a win in the starting position."> E. 1.5
Black to move after 64.Kxh8
 click for larger viewAccording to Shredder this is a draw
Bottom line is that 56...gxf4+? allowed White to save himself while 56...g4! would have won. |