Mate in 3: rook to d7 (e7)
c9-22348naming 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 1760 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 d2, queen g3, rook e7, bishop g1 c2, knight f6, pawn b3 h3 a4 c4 d4 f5 h5.
Black: king b7, rook a8, bishop d7, pawn a5 d5 g5 b6 c6 h6.
13 white and 9 black pieces are on the board; the puzzle position arises after move 28.
The position in numbers
White are ahead by 16 points of material (30 against 14; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on d2, the black king on b7.
It is White to move on move 28, with 52 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 7 pawns, Black 6. Files fully open (no pawns of either colour): e — natural highways for the rooks and queen. Half-open for White: g.
White hold the bishop pair, an edge in open lines. The White king has 7 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
28. Rxd7+ Ka6 29. Qc7 dxc4 30. Qb7#
Why it works
- Best move. rook to d7 is exactly what the engine plays (#2).
- queen to c7 develops smoothly.
- Precise: queen to b7 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Ka6, then Qc7 and you win the bishop.
Move by move
- 28. Rxd7+ — rook to d7 (capture) with check
- Ka6 — king to a6
- 29. Qc7 — queen to c7
- dxc4 — pawn to c4 (capture)
- 30. Qb7# — queen to b7 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.
Royal fork
A fork with check: the king must move, and the second piece is lost.
A royal fork is a fork with check — one of the two targets is the king itself. The check must be answered first, so nobody is left to rescue the second piece. Look for squares where your piece gives check and simultaneously attacks an undefended queen or rook. It is the most reliable fork of all, because your opponent literally has no choice.
About this position
These pieces come from starting position #637.
SP-637 · BastionScout — A c- or f-file king with at least one knight out on the edge.
The king starts on c1, the rooks on a1 and f1, the queen on e1.
The king already stands on c1, so castling long moves only the rook, from a1 to d1.
The bishops stand on d1 and g1; their long diagonals reach h5 and a7 once the e- and f-pawns step aside.
One second-rank pawn starts with no defender at all: g2.
The setup belongs to the BastionScout family; read right to left it becomes position 232.
The engine's main line opens with e4, putting a pawn straight into the centre.
Morozov Balance Index: 39 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +21 centipawns for White (depth 44, 400 000 000 nodes).
In 50 self-play games White scored 57.0% (95% CI 43.3–69.7%).
Explore position #637Provenance
Mined from the project's engine self-play games.
Pack 013 · SP-637
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