In this position, what is a clear line in which Black escapes from perpetual check?
[FEN "2k5/7p/p1Q3p1/3pP3/1r2qP2/1P4PK/P7/8 b - - 0 1"]
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1I only see lines where black "escapes" from perpetual check by running into a helpmate (e.g., on h8 or on h5). Needless to say, that perpetual check is the better choice for black.– Sir CornflakesCommented Apr 24, 2018 at 16:04
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1@jknappen this is a CT solution to a puzzle.– Jossie CalderonCommented Apr 25, 2018 at 4:36
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2 Answers
It seems that the black king can escape via a5/
[FEN "2k5/7p/p1Q3p1/3pP3/1r2qP2/1P4PK/P7/8 b - - 0 1"]
1...Kb8 2.Qd6+ Kb7 3.Qd7+ Kb6 4.Qd8+ Kb5 5.Qb8+ Ka5 {Kc5? 6. Qd6 Kd4?? 7.Qxb4} 6.Qc7+ Rb6 7.Qc5+ Rb5 8.Qc7+ Kb4 {and you go for the hills.}
edit: 5.a4+!, noticed by @jknappen, is problematic. The right solution is rather to bring the king to a7 before covering checks with ...Rb7, as in @InertialIgnorance 's answer which should become the accepted one.
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and what happens after 5. a4+ guarding the field b5 with the pawn? Will black win with a rook sacrifice? Commented Apr 25, 2018 at 13:25
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@jknappen : uuum, good remark. Giving back the rook is, to say the least, too complicated for the final position of a CT exercise. I've to spend more time on the position tonight, maybe Kb6-a7 and bringing down the rook to b6/b7 is rather the way to go.– EvargaloCommented Apr 25, 2018 at 13:56
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@jknappen As Evargalo said, Black needs to move the King back down. Komodo says Black is still winning after 5...Kc6, but there's a lot of work to do. Commented Apr 25, 2018 at 20:47
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@jknappen The mate threat of ...Qh1+ and Qh5# is looming, so if Black plays Rb5 he can escape to b4. Commented Apr 25, 2018 at 21:25
To escape from perpetual check when up material in an endgame, a good strategy is to try to surround your King with your extra pieces. In this case, that would be your Queen and Rook, and maybe a few of your pawns. Sample line:
1...Kb8 2. Qd6+ Ka7 3. Qc7+ Rb7 4. Qc5+ Kb8 and now White has a few options:
a) 5. Qd6+ Kc8 6. Qc6+ Rc7 (7. Qe8+ Kb7) 7. Qa8+ Kd7 and Black escapes.
b) 5. Qf8+ Kc7 6. Qe7+ (6. Qd6+ Kc8 transposes to line a) Kb6 7. Qd6+ Kb5!! 8. a4+ Ka5 9. Qc5+ Rb5!! and Black wins. White cannot take Rb5 with the a-pawn due to the threat of Qh1#
I found all the moves myself up until move 7 in line b). Komodo came up with the brilliant idea of 7...Kb5, 8...Ka5, and 9...Rb5
answered Apr 25, 2018 at 20:43
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+1. I don't need to correct my answer anymore since you show the right variation.– EvargaloCommented Apr 26, 2018 at 9:19
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@Evargalo From a practical standpoint, I think your answer still has merit. If White doesn't find 5. a4+, then the game is won quicker. If White does find the move, Black is still winning but it will take a while to prove. Objectively 2...Kb7 isn't best, but in a situation such as time trouble over the board it's perfectly valid. Commented Apr 26, 2018 at 9:30