Test your chess: Reitstein problem 46: dancing with the rooks

Black to play and win.

T Gannholm v DA Walker 1978

(I) black to play and win: find the line played in the game;

(2) find the even stronger line, which requires some rook dancing.

Solution

I immediately saw the solution here, the 'trick' 1…Rb3!: the only knowledge needed being that two pawns on the sixth (after 2 ab cb) beat a rook. Then 2 Rc1 Rb2+ and picks up the a2 pawn. And 1…Rb3 was played in the game, and won.

However, this is the first puzzle in the book so for where the engine surprised me. Whilst Stockfish agrees black is winning after 1…Rb3, it gives the best defence as 2 Rh1! when there is some fight left in the game. If 2…Rc3 3 Rh7+ and the rook can swing behind the a pawn, giving black some conversion difficulties. Properly played, black is winning – 2..Kg7 – but it is not entirely resignable.

Therefore, Stockfish prefers the surprising 1…Rb2! which actually relies on zugzwang. White is forced to play 2 Re2, when 2…Ke6(say) forces either 3 Kf1 or 3 Ke1. If the former, then 3…Rb1+! 4 Re1 Rb3! is an improved form of the game solution because the rook can't move to the h file. And if 3 Ke1 then 3…Rb1+ 4 Kf2 (4 Kd2 Ra1) 4…Rc1.

Very nice: dancing with the rooks.

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