Mate in 3: queen to b7 (b1·2)
c9-25861naming tag (square·N)Opens in the app if installed, otherwise downloads the APK.
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
How to recognize this tactic
In Chess960 the pieces start on unfamiliar squares, so tactics appear earlier and from unusual angles. Do not trust classical patterns — read the actual lines of the bishops, the rooks and the queen from where they really stand in this position.
In a mate in three every move must be forcing; the defender should never get a free tempo. Find the check or threat that herds the king, calculate the single defence to each, and confirm the net closes on the third move.
General method: before you move, list the forcing candidates — every check, every capture, every direct threat — and calculate those first. The solution to a tactic is almost always among them.
Position on the board
White: king h2, queen b1, bishop c3, pawn a2 f2 d3 c4 e4.
Black: king h8, pawn d5 c6 g6 b7 g7.
8 white and 6 black pieces are on the board; the puzzle position arises after move 30.
The position in numbers
White are ahead by 12 points of material (17 against 5; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on h2, the black king on h8.
It is White to move on move 30, with 38 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 5 pawns, Black 5. Files fully open (no pawns of either colour): h — natural highways for the rooks and queen. Half-open for White: b, g.
The White king has 5 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
30. Qxb7 d4 31. Bxd4 Kh7 32. Qxg7#
Why it works
- Best move. queen to b7 is exactly what the engine plays (#2).
- Spot on — bishop to d4 (#1).
- Precise: queen to g7 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead d4, then Bxd4 and you stay on top.
Move by move
- 30. Qxb7 — queen to b7 (capture)
- d4 — pawn to d4
- 31. Bxd4 — bishop to d4 (capture)
- Kh7 — king to h7
- 32. Qxg7# — queen to g7 (capture) and it is checkmate
Types in this puzzle
Supported queen mate
The queen delivers mate face to face, protected by a friend.
The supported queen mate is the most common pattern of all: the queen lands next to the king and mates because a friendly piece or pawn protects her. The king is helpless — capturing is impossible, and the queen covers every neighboring square herself. Hunt for a protected square beside the enemy king: a knight, bishop or pawn eyeing it turns her invasion into mate. Verify one thing — that the square really is defended, or the king eats her.
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.
Queen endgame
Queens on an open board — precision above all.
Queen endgames are treacherous: the queen reaches everywhere, and one slip turns a win into perpetual check. The signs are few pawns, exposed kings, and checks hanging in the air. Tuck your king away early, and use your own checks to bring the queen closer or push your passer with tempo. The typical mistake is grabbing pawns while leaving your king exposed to endless checks.
About this position
These pieces come from starting position #101.
SP-101 · RampartGuard — A wing king (b/g) with no knight on the a- or h-file.
The king starts on g1, the rooks on e1 and h1, the queen on a1.
The king already stands on its castled square, so castling short moves only the rook, from h1 to f1.
The bishops stand on c1 and d1; their long diagonals reach h6 and h5 once the d- and e-pawns step aside.
The pawn on f2, g2 is defended by the king alone — the same soft spot f2 is in the classical setup.
The setup belongs to the RampartGuard family; read right to left it becomes position 858.
The engine's main line opens with d4, putting a pawn straight into the centre.
Morozov Balance Index: 16 of 100 — class D — largest edge. Engine evaluation of the starting position: +39 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #101Provenance
Mined from the project's engine self-play games.
Pack 012 · SP-101
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