The Critical Position

In "Surprisingly Strong Move", I briefly described a situation where a move I played in desperation proved winning in all lines. The opportunity was made possible by an error in an equal position. As we had both been shuffling rooks and kings for twenty moves, it was not an easy matter for my opponent to discern that a critical position had been reached.

Black to move

Black played 52...Kd6.

Both 52...Rg1 and 52...Rh1 leave White with an advantage so slight that the game should end as a draw.

a) 52...Rg1 53.f3

Alternately, 53.Ra5+ Kd6 54.f3 seems about the same. 

53...Rb1 54.Ra6 Re1 55.Rb6 and Stockfish thinks 55...Ra1 is best.

b) 52...Rh1 seems slightly worse than Rg1 in the initial engine evaluation. But, the main line continues 53.Ra5 Kd6 54.d5 (else matters don't change) 54...Rh2 55.f3 exd5 56.Rxa6 Kd7 57.Kxf5 and the tablebases indicate draw.

Black to move

Tablebase Draw