My thanks to IM Paul Littlewood for posting this on Facebook. It’s Black’s move in this position from the recent game Awonder Liang (2587) v Santosh Gujrathi Vidit (2726) (Aimchess US Rapid Preliminaries). What would you suggest?
This position is mostly about understanding king and pawn against king, but there’s another subtlety as well.
The first point is that if Black trades queens the position is just a draw as White has the opposition. If you don’t know this already, check it out and make sure you learn it. So that rules out 108.. Qxg3+.
The second point is that 108.. f5 wins after 109. Qxg4+? Kxg4! but White can draw with, for example, 109. Kf2! Qxg3+ 110. Kxg3.
Black wants to force White to trade queens, so might instead try 108.. Kf5. Now if White trades queens he loses, but he has a familiar stalemate trap: 109. Kh1! and Black can’t make progress. The tablebases confirm that the position is drawn.
There is a win, though: 108.. Kh5!. White can still try the stalemate trap with 109. Kh1 but the difference is that Black now wins with 109.. Qh4+!, whether White trades or plays Kg2 here. For instance 110. Kg2 Qxg3+ 111. Kxg3 Kg5! 112. Kf3 Kf5! taking the opposition.
If you’re not sure about this, set up the board and play it out yourself. This is all vital knowledge for all improving players. If you’re a chess teacher, make sure all your students know this as well.
What happened in the game? Did the 2726 rated GM find the winning move? Sadly not: the game continued 108.. Kf5? 109. Kh1! and the game was drawn 50 moves later. Did you manage to do better and see that 108.. Kh5! was the winning move?
In rapid chess, especially after more than a hundred moves, it’s not so easy, even for the best of us. In the same way, top golfers sometimes miss short putts. It’s what life is all about, isn’t it?