Cordingley puzzle 37

May 7, 2013

Black to play and win.

Solution

I think this is virtually self evident: the first move I thought of was really the only move, and all that was needed was some computation.

I remembered the maxim 'if you see a good move, look for a better one', and thought that 1…Qh5+ might be even better than 1…Rg4; but analysis showed it was no better, and in fact worse.

When I checked my analysis with Houdini, I found it odd that, at least until it had thought for a minute or so, it preferred (after 1…Rg4) 1…Qh7+ to 1… Qh6+; though after a while assesses them as precisely equivalent- which they must be, because the queen later comes down the h file. I fail to see why Houdini initially preferred h7.

I stopped my main line analysis at the position below, knowing that there would either be a quick finish, or more likely a long but inevitable endgame.