Mate in 3: queen to g6 (b1)
c9-18953naming 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 d1, queen b1, rook c1 f1, bishop e5, knight g3, pawn a2 d2 e2 f2 h2 b3.
Black: king g8, queen b7, rook f3, bishop a8, knight g2, pawn b4 h6 a7.
12 white and 8 black pieces are on the board; the puzzle position arises after move 18.
The position in numbers
White are ahead by 8 points of material (31 against 23; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on d1, the black king on g8.
It is White to move on move 18, with 43 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 3. Files fully open (no pawns of either colour): c, g — natural highways for the rooks and queen.
The White king has 1 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
18. Qg6+ Kf8 19. Bd6+ Qe7 20. Rc8#
Why it works
- Best move. queen to g6 is exactly what the engine plays (#2).
- Spot on — bishop to d6 (#1).
- Precise: rook to c8 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Kf8, then Bd6+ and you stay on top.
Move by move
- 18. Qg6+ — queen to g6 with check
- Kf8 — king to f8
- 19. Bd6+ — bishop to d6 with check
- Qe7 — queen to e7
- 20. Rc8# — rook to c8 and it is checkmate
Types in this puzzle
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.
Absolute pin
A piece is pinned against its king — it cannot legally move.
An absolute pin freezes a piece on the line between its own king and your long-range attacker: moving it is simply illegal. The pattern is three units on one straight line — your bishop, rook or queen, an enemy piece, and the enemy king behind it. A pinned piece neither attacks nor defends anything: treat it as if it were off the board. Pile up on it, ideally with a pawn, because running away is against the rules.
About this position
These pieces come from starting position #865.
SP-865 · ThroneScout — A central king (d or e), but with a knight posted out on the a- or h-file.
The king starts on e1, the rooks on c1 and f1, the queen on b1.
The kingside rook already stands on f1, so castling short moves only the king, from e1 to g1.
A bishop starts in the corner on a1: it has a single diagonal, which the b-pawn unlocks, running out to h8.
The second rank carries 2 pawns with no defender at all: g2, h2.
The setup belongs to the ThroneScout family; read right to left it becomes position 91.
The engine's main line opens with b3.
Morozov Balance Index: 83 of 100 — class A — most balanced. Engine evaluation of the starting position: +16 centipawns for White (depth 46, 400 000 000 nodes).
Explore position #865Provenance
Mined from the project's engine self-play games.
Pack 012 · SP-865
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads