Unlock your Genius – November 2008 (Problems)

by dlwyatt, Ohio, Saturday, November 08, 2008, 14:15 (6245 days ago) @ AndreaCoda

Well, it looks like White can't allow Rxe4+ if he wants to have any hope of winning, so Bxa4 is out. With that in mind, we can more or less ignore the relative strengths of the minor pieces, since White will be forced to play Bf5 in the next 1-2 moves, and Black will likewise be forced to reply Nxf5 to avoid checkmate.

The question seems to be whether to play Bf5+ immediately (intending Rf7 and Rxf6+ after the forced sequence Bxf5 Nxf5 exf5+ Kh6 Rf7), or play h5+ Kh6 Bf5 Nxf5 Kxf5, and instead use the king to penetrate when the time is right.

Bf5+ immediately is much more forcing, and both the f6 and d6 pawns will fall no matter what Black does, but he can get his rook behind his passed a-pawn (this is probably the "trick" Tony mentioned), ie:

1. Bxf5+ Nxf5 2. exf5+ Kh6 3. Rf7 a3 4. Rxf6+ Kg7 5. Rxd6, and now Black has Re4+ followed by Ra4. The position is still alive, as Black's king is under all sorts of pressure from white's king, rook, and multiple passed pawns all up in his face, but Black is two moves away from making a queen, if he is given the time to do it. I'll have to spend some more time looking at that position to see who wins first.

By the way, this is the reason for considering the h5+ and Kxf5 line; White's king keeps the black rook off e4 long enough to make sure the it's the white rook behind the a-pawn. It doesn't win 2 pawns right off the bat like the other line, but may be the safer alternative, and White should still be able to produce a lot of pressure once his king moves to e6, captures on d6, and starts to support the passed d-pawn.