Mate in 3

Rxq, Kxr, qe2+ Kg1, Rg3+, Kh1, Qg2, is mate in 4.

Originally posted by ActiveKing
Rxq, Kxr, qe2+ Kg1, Rg3+, Kh1, Qg2, is mate in 4.

Originally posted by David113
[fen]8/kq1R4/3R4/8/7p/7Q/8/K7[/fen]

White to play and mate in 3 moves

1...Kb8 2. Qb3 Qxb3 3. Rf8#
1... Ka8 2. Qg2 Qxg2 3. Rf8#
1... Qc7 2. Rxc7+ Kb8 3. Qc8#
1...Qxd7 2. Qxd7+ Kb8 3. Rf8#

Originally posted by SwissGambit
1. Rf6 (zugzwang)

1...Kb8 2. Qb3 Qxb3 3. Rf8#
1... Ka8 2. Qg2 Qxg2 3. Rf8#
1... Qc7 2. Rxc7+ Kb8 3. Qc8#
1...Qxd7 2. Qxd7+ Kb8 3. Rf8#

Originally posted by David113
SOLV'D😀

Originally posted by heinzkat
Composed by ...?

Originally posted by David113
SOLV'D😀

Originally posted by Frank33
A small error - when 2. Qxd7+ the queen cannot move there - the rook is on f6 and in the way. However, if the rook is simply moved to g6 originally there is no problem with this.

Originally posted by heinzkat
Think twice before you speak once, they say...

1. Rf6 Qxd7 2. Qxd7+ is, in fact, possible! I think you somehow misplaced Rf6 'mentally' on f5 (!?)

Also, your proposed 1. Rg6 does not work due to 1. ... Ka8!, I think. (2. Qg2 Qxg2 3. Rg8+ Qxg8)
1. Rg6 doesn't work either due to 1. ... Kb8, and now 2. Qb3 Qxb3 3. Rg8+ Qxg8.
There is a reason 1. Rf6 is the only correct solution.

Originally posted by SwissGambit
"why must this move be the key, and not other moves that appear to have the same idea?"

Originally posted by heinzkat
Often the composer wants the wrong tries to be tried, I think. At least, I would want to (although I have never composed anything decent).

Originally posted by SwissGambit
Old-school composers like Sam Loyd were famous for making the key move the most unlikely looking move on the board. Case in point:

Sam Loyd
"Excelsior"
[fen]n1rb4/1p3p1p/1p6/1R5K/8/p3p1PN/1PP1R3/N6k w - - 0 1[/fen]
Mate in 5

Nowadays, composers tend go for several thematic tries, without much concern about making them more obvious than the key.

Originally posted by heinzkat
5. bxa8=B#

Originally posted by SwissGambit
Correct. Allegedly, Loyd won a dinner bet on this problem. It was created to fool another problemist, who was asked to pick the least likely piece to give mate - and he chose Pb2!