My favourite pawn endgame

Black to move.

While playing on lichess.org’s excellent Puzzle Themes I discovered a pawn endgame unlike any I’d seen previously. The setup is as seen on the right, viewed from White’s perspective. It looks simple but it hides remarkable depths!

In the source game the puzzle originates from, Black played 1…b5 and went on to draw. Indeed, a cursory glance at the position suggests that the two sides are engaged in a pawn race in which Black is a half-move ahead (which is to say, Black queens first but White queens immediately thereafter) and as such is likely to end in a draw, although if anyone has chances for more it’d have to be Black.

Surprisingly, the correct assessment is that in the initial position Black has only one (very counterintuitive) move that holds the draw!

Moreover, if White agrees to a gentlemen’s pawn race and responds to 1…b5 with 2. h4, he will lose! Another surprise may be found over a dozen moves deep in the form of a forced queen trade I’d never have guessed possible. Finally, this endgame proved to be an example of something I’d previously sought and failed to discover - namely a pawn endgame in which it is good to place one’s king on the imminent enemy queen’s diagonal!

I refer the interested reader to this study of mine in which the position is analysed (in chapter 6).