Nice endgame study

White to move and win.

Qh7 ~
Kg3+ Bh2
Qxh2#
seems to work- or
Qh7 Be3
Qh6 Ame thing.

Originally posted by Alethia
Qh7 ~
Kg3+ Bh2
Qxh2#
seems to work- or
Qh7 Be3
Qh6 Ame thing.

What if your ~ move is Bh2? Then 2. Kg3+ doesnt work and Kg4 is followed by g1Q+

The idea is to make sure black's dark squared bishop can't move (also avoiding any promotion threats), and threatening either Qg3 (with the white bishop on f1, zugzwanging white) and Kg3 with mate on the h-file, maneuvering such that a dark square on the h-file can be reached by the queen.

For instance:
1.Qb8 Bb5 (Bd3 then 2.Qf3! Bf1 3.Qg3 wins) 2.Qg4 Bc6 3.Qd1 Be4 4.Kg3! Bg6 5.Qc1 (or Qa1) Qh5 6.Qh1!(foring the bishop to move away from the h-file) followed by Qh8+ and win

or another try
1.Qb8 Bc4 2.Qe5 Ba6 (Bd3 then Qg5) 3.Qc7 Bd3 (Be2? 4.Qg7 Bf3 5.Qa1 followed by Kg3 and as above) 4.Qf4 Be2 5.Qg5! Bf3 6.Qc1 Be2 7.Kg3 and same as above

The variations are numerous, but the ideas are the same, and white cannot avoid the maneuver.

edit: nvm

This one is tough somehow. I also figured out that Qb8 has got to be the first move and that White has to get Black into Zugzwang somehow. But all the other moves seem so randomly, I cant recognize the idea yet.

They are not random at all, once you understand how white wants to finish (with Kg3), and hence what black tries to avoid .