Originally posted by WulebgrYes, but not convincingly. It is much more complicated and interesting than I initially thought (intuitively but quite naively). The key in defending against the three pawns is indeed being able to maintain the king in the middle file (or at safe distance below), covering the pawn advance as well as the target promotion squares. The king has to prevent the pawns from setting up the 'fork' unless he can jump in the hole and is not forced to move out again - for that he needs the tempi on the other side. And vice versa for the opponent. This way, it becomes a tempo/zugzwang game between the defending and attacking side.
It is finished.
Game 1927044
In the starting position, white cannot afford losing the one-time opportunity to play c5 immediately. If, as in the game, he plays 1.Kg2, then black does the same with Kb7 (and NOT g4 because that gives white a second chance to advance and win with a6 as in the game). After 1.Kg2 Kb7, white is in zugzwang and has nothing better than pushing a pawn, or giving up the king position. It could go: 2.b5 f4 3.c5 Kb8! 4.a6 Ka7! and white's tempi are consumed (c5? Kb6!) and he needs to play the king e.g. 5.Kf2? h3! 6.Kg1 f3! etc..... and black wins.
If, however, white plays 1.c5! then black loses when he mimicks white's moves because white promotes first with check e.g. 1.c5 f4 2.a6 h3 3.b5 g4 4.b6+ Kc3 5.a7 g3+ 6.Kf3 h2 (Kb7 then c6+) 7.a8=Q+ the check makes all the difference .... Kxc5 8.Kxf4 and the queen covers the promotion square.
After 1.c5!, a king move loses as well e.g. Kb7 2.b5 Kb8 (or h3 3.Kg3 g4 4.b6! f4+ Kh2 etc. until black is out of pawn moves and has to move his king) 3.a6 Ka7 4.c6 Kb6 5.Kg1 and the white king is well placed to stop or eat all the pawns and forceblack to move his king.
I am sure this is not comprehensive (but hopefully correct) and any corrections/add-ons would be appreciated.
Originally posted by WulebgrYes, the first section was trying to explain what could happen after 1.Kg2 as was played by your opponent. You could have reversed all the issues by playing Kb7 instead of what you played. White then is in zugzwang, and his 'race' solution with c5, threatening a5 etc... isn't possible anymore. And black could win.
The document from which I took the problem gives only
1.c5 f4 2.a6 h3 3.b5 g4 4.b6+
You offer that much and more.
However, as my opponent played it differently, did I miss an opportunity to draw?
It is a difficult endgame, and because of the tempo/zugzwang issues, there is only one good move which has to be worked out at several points throughout the game. Easy to make a mistake.
Originally posted by Mephisto2So, it was the win that I missed, not a draw. 😳
Yes, the first section was trying to explain what could happen after 1.Kg2 as was played by your opponent. You could have reversed all the issues by playing Kb7 instead of what you played. White then is in zugzwang, and his 'race' solution with c5, threatening a5 etc... isn't possible anymore. And black could win.
It is a difficult endgame, and because ...[text shortened]... ove which has to be worked out at several points throughout the game. Easy to make a mistake.
Originally posted by WulebgrI'd like to accept, but I can't. :'(
It continues: Game 1929390, and another in progress.
D
Originally posted by WulebgrWell, you did the attacking part (your pawns) correctly, but you were VERY lucky that white blundered 5.Kf3?? where he had a won position after 5.Kg2! , e.g. g4 6.Kg1 and wins (f3 Kf2 or h3 Kh2 going in the hole next move with black to move, or g3 Kg2 with same result).
It continues: Game 1929390, and another in progress.
Your reaction to the (bad) first white move was wrong: 1.a6? Kb6! (and NOT f4) and if 2.b5 then h3! wins after 3.Kg3 g4! because white has to move first and give up the defense agaisnt the pawns moving forward. An completely symmetrical example of mutual zugzwang.
Thanks Mephisto2.
Based on your analysis, I imagine that 1...f4 was wrong again in Game 1929686. White could have won with 3.a6 Kg7 4.Kg2! g4 5.Kg1 h3 6.Kh2 with yet another example of symmetrical and reciprocal zugzwang.
Originally posted by WulebgrYou are right, f4 was the wrong move. 1.b5? h3! wins. Example: 2.a6 Kb6 3.c5+ Ka7 4.Kg3 g4 5.c6 Kb6 and white has to give up the defense (6.Kh2 f4 etc.).
Thanks Mephisto2.
Based on your analysis, I imagine that 1...f4 was wrong again in Game 1929686. White could have won with 3.a6 Kg7 4.Kg2! g4 5.Kg1 h3 6.Kh2 with yet another example of symmetrical and reciprocal zugzwang.