Mate in 3: queen to b4 (g4)
c9-27924naming tag (square·N)The tactical motive
Chess960 twist: use the unusual starting setup of the pieces.
Mate in 3: a forced sequence that ends in checkmate.
Difficulty 1630 ShuffleRating — for advanced tacticians.
White to move — find the best continuation
Position on the board
White: king d1, queen g4, rook c1 e1, bishop f3, knight f2 b3, pawn a2 b2 g2 h4 f5 c6 d7.
Black: king d6, queen g7, rook d8 g8, knight f7 a8, pawn d5 a6 e6 g6 b7 h7.
14 white and 12 black pieces are on the board; the puzzle position arises after move 21.
Solution & explanation
Main line
21. Qb4+ Kc7 22. Qxb7+ Kd6 23. Rxe6#
Why it works
- Best move. queen to b4 is exactly what the engine plays (#2).
- Spot on — queen to b7 (#1).
- Precise: rook to e6 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Kc7, then Qxb7+ and you stay on top.
Types in this puzzle
Ladder mate
Two heavy pieces climb line by line, cutting off every retreat.
The ladder mate uses two heavy pieces climbing rung by rung: one cuts the king off along a line, the other checks on the next line, driving him toward the edge. It is the classic two-rook technique — check, the king retreats one rank, the other rook checks, until mate on the last rank. The only danger is the king creeping close enough to attack one of your rooks. If it does, simply slide that rook to the far side of the same line.
Mate in 3
A forced checkmate in three moves.
Mate in three is a forced staircase: each of your moves narrows the opponent's choices, and the third one ends the game. Look for the start among checks and sacrifices — quiet first moves are rare in mating problems, but deliciously sneaky. Keep the tree in your head: every defense gets its own branch. Do not stop calculating after move two — see the final mating picture with your own eyes.
About this position
These pieces come from starting position #344.
SP-344 · ThroneScout — The king starts on d or e while at least one knight begins in a corner.
The king starts on d1, the rooks on c1 and g1, the queen on f1.
Castling long simply swaps the two pieces: the king on d1 and the rook on c1 trade places.
The bishops stand on b1 and e1; their long diagonals reach h7 and a5 once the c- and d-pawns step aside.
The second rank carries 2 pawns with no defender at all: b2, h2.
The setup belongs to the ThroneScout family; read right to left it becomes position 333.
The engine's main line opens with c4.
Morozov Balance Index: 37 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +30 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #344Provenance
Mined from the project's engine self-play games.
Pack 012 · SP-344
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