Originally posted by crazyblue Is it too difficult? Here's a hint: White will move queen twice and a rook once (not necessarily in that order) 😉
1.Rh1! and black is in zugzwang. White threatens mate on d6 or c6 with the queen if black plays a knight move. But after a bishop move (Bd7 or Be8) then 2.Qb1 and 3.Qb4# do the job. Except when black plays 2. ... Bb5 (back to the original square) then 3.Qg1# does it. That is why only Rh1 works.
After not being able to solve it, I tried a couple of programs, but the best they would do was 4 moves. So I got out my old Fidelity Chess Challenger 10 and put it in Mate in 2 mode (1 hour per move). No luck. Then I tried the Postal Chess mode (1 day per move) and it solved it! Image that, a 30 year old computer chess game did the trick! 😀
Then I came back here and saw that it was solved!! That stupid slow Chess Challenger!!! 😴
Originally posted by twilight2007 [fen]4KBkr/6Pp/7P/4P3/8/3P4/5p2/8 w f2 0 1[/fen]
I got this one from a friend. Reach a theoretically won position or zugzwang.
1.Be7 f1Q 2.Bf6 threat gh8 2...Qxf6 3.gxh8Q+! [not 3.exf6 stalemate] 3...Qxh8 4.d4! zz 4...Qg7 5.hxg7 h5 6.e6! The K has to move in any case, so this pawn is the right one to push 6...h4 7.e7 h3 8.Kd7 h2 9.e8Q+ and Black has come out one tempo too slow.