Last week I asked you for White’s best move in this position which might have arisen in the game Treybal – Balla (Bad Pistyan 1922). (Treybal chickened out of the exchange sac on f6 which might have led to this position and the game was drawn a few moves later.)

A few of you found the only winning move here: the remarkable and unexpected Kf1!

White has a slow threat of Rb4 followed by Rb8+, meeting Rd8 with Rb7, and could also throw in Rxh4 first if he wanted.

But first he has to prevent any Black checks, and Kf1 is the only way to do that. Try it out for yourself, and, if you still don’t believe me, put it on an engine.

Congratulations to everyone who managed to find the solution!

Look out for some more puzzles from 100 years ago both here and in my Chess Improver blog posts.