For the last time, I have Christmas puzzles for you taken again from the CHESS magazine.
a) Black stands legally checkmated.
b) White stands legally checkmated.
c) White can give checkmate in half a move.
d) Black can give checkmate in half a move.
These are the solutions:
|1||1. Na8! Kxb3 2. Rh3+ Kc4/Ka2,4 3. Nb6/Ra3#|
1. - b4 2. Na1 ~ 3. Ra5#
|2||1. Bf5! K~ 2. Bxg4 ~ 3. Bh5 ~ 4. g4 and White has stalemated himself!|
|3||White can only retract h2xRg3 and then mate with 1. Qxe2#.|
Rectracting h2xPg3 is not legal: the black pawns would have had to capture eight times, but only seven are missing.
If we retract b2xPc3 or b2xRc3, it would have been impossible for the black king to move to the first rank.
We can't retract a king move due to illegal checks.
Retracting a queen or a rook move doesn't leave any possibility to mate in one.
|4||a) +wKg6, +bKe4 |
b) +wKb2, +bKd1 (last move was 1.- a1=B#)
c) +wKb4, +bKd4: White already picked up the black pawn and completes the en passant capture d5xe6 e.p.
d) +wKh8, +bKc8: Black completes castling long and puts his rook to d8.