Speed Kills

While playing this ending, I first thought that we had reached a simple drawn position. Then, my opponent erred. I sensed (correctly) that I was now winning, but managed to throw it away. Later analysis showed that it should have been drawn until my error gave my opponent a winning opportunity, but perhaps not an easy one to find.

Black to move

41...f6??

I rejected hastily 41...f4+, although it should have been clear to me that 42.gxf4+ Kf5 43.Kd4 Kxf4 leads to a pawn race where both players promote on the same move--a draw.

Stepping back with 41...Ke6 also allows Black to regain the opposition if White tries to advance his king.

42.Kd3

My first clue that I had missed something instructive in this ending was the website's game analysis calling this move a miss. Using the retry function, I found the idea, but further analysis showed that it was more intricate than I then thought.

White's winning idea is to transfer the king to h3, then create a passed pawn.

42.Kf2! Kd5 43.Kg2

Black to move

Analysis diagram

43...Ke5

If Black tries 43...Kc4, White's breakthrough takes place instantly for Black's king cannot get back into the square of the pawn. The pawn on f6 blocks the diagonal route after 44.g4 fxg4 45.fxg4 Kd4 46.gxh5.

44.Kh3

Without some calculation, I assumed that Black's b-pawn would promote before White's kingside pawns could break through, but the variation just above shows that is not true. Instead. Black's king must stay on the kingside. This also fails.

a) 44...Ke6 45.g4! f4 46.gxh5 Kf5 47.h6

Black to move

Analysis diagram

47...Kg6 48.Kg4 Kxh6 49.h5 f5+ 50.Kxf4 Kxh5 51.Kxf5+-

b) 44...f4 45.g4 f5 46.g5 and now Black's king is tied down to stopping the passed g-pawn allowing White's king to run to the b-file.

42...Kd5

I was thinking that we would shuffle our kings back and forth and agree to a draw.

43.g4??

Black to move

43...fxg4 44.fxg4 hxg4 45.h5 f5??

I hallucinated that my king could stay in the square.

45...Ke6 leads to an easy win.
45...g3 also leaves Black with a decisive advantage

46.h6+-

I blitzed out a few more moves because my opponent was low on time, but resigned when it became clear that my opponent would finish easily with the 20 seconds or so remaining.