Fundamentals (part 28)

Leo Keely (174) - Spanton (173)
Hastings Challengers 1998-99

White to make his 33rd move

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33.a3?
This loses, as does 33.g3?, but White has two ways to make a draw: 33.c4+ and 33.a4! The latter is better because it sets a trap.
After 33.c4+ bxc4 34.Ke3 c5 (if 34 ...a4 then 35.a3) 35.dxc5 Kxc5 36.c3 Black cannot make progress, eg 36...Kb5 37.Kd2 Ka4 38.Kc2 Ka3 39.Kb1 etc.
After 33.a4! the impulsive 33.bxa4? loses to 34.c4+ Kd6 35.c5+! Kd7 36.Kc3 Kc8 37.Kb2 Kb7 38.Ka3 Ka7 39.Kxa4 Ka6 40.c3 Kb7 41.Kxa5 Ka7 42.c4 Kb7 43.d5 etc, eg 43...Kc8 44.d6 Kd7 45.dxc7 Kxc7 46.Ka6 and Black will lose the c6 pawn.
However after 33.a4! the analysis engines Stockfish10 and Komodo10 show Black draws with 33...Kd6 and the transpositional 33...h6, eg 33...Kd6 34.c4 (but 34.g3? loses to 34...bxa4, eg 35.c4 a3 36.c5+ Kd7 37.Kc3 a4 when White is in zugzwang) b4 when neither side can make progress.
After the text it is Black to play and win.
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33...a4?
33...c5 wins easily, eg 34.dxc5 Kxc5 35.Ke3 Kc4 36.Kd2 a4 etc.
After the text it is White to play and draw.
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34.g3
The engines show 34.c4+! draws after 34...bxc4+ 35.Ke3! c5 36.dxc5 Kxc5 37.c3.
34...c5 35.dxc5 c6?
Over-finessing - 35...Kxc5 wins.
After the text it is again White to play and draw.
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36.Ke3?
Drawing is 36.c4+ bxc4+ 37.Ke3.
The game finished:
36...Kc4 37.Kd2 h6 38.Kd1 Kxc3 39.Kc1 Kc4 40.Kb2 Kd4 41.Kc1 Kxc5 42.c3 Kc4 0-1