Daily chess puzzle

Today’s problem is from the recent St Louis 2019 blitz tournament.

As has been my custom on this blog for a while, I adopt the style of only saying which side is to play: and not giving an idea if the move wins or otherwise, unless on occasion I think signposting would be helpful. Instead, the problems are posed with the instruction to decide what you would play, as in a game.

White to play

variation from Kasparov v Caruana, St Louis 2019

Solution

Garry could have won with 1 Bd8!!

If 1…Re3 2 Bf6; so 1…Rd7 is forced, met by 2 ed Nd4 3 Bg5 Ne6+ 4 Ke5 Kf7[] 5 d8(Q) Nd8[] 6 Bd8

And since h8 is a black square, this is a win. My engine happens to say mate in 20, but that is worth nothing.

FEN

5k2/2BP3p/4P1p1/8/5K2/3r4/2n4P/8 w – – 0 1