Winning blow: queen to c8 (c7)
c9-16470naming 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.
Winning tactic: there is a move that gains a decisive advantage — find it.
Difficulty 1700 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.
This position hides a concrete tactic that wins material or mates. Start with the most forcing candidate moves — checks, captures and threats — and calculate each to a clear end before choosing; the winning line is usually the one the opponent cannot meet.
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 c1, queen c7, bishop d8, pawn c2 f4 f6.
Black: king a8, queen e2, knight d4, pawn d5 b6 e6.
6 white and 6 black pieces are on the board; the puzzle position arises after move 37.
The position in numbers
Material is level — 15 points of pieces on each side (pawn = 1, knight and bishop = 3, rook = 5, queen = 9).
The white king stands on c1, the black king on a8.
It is White to move on move 37, with 23 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 3 pawns, Black 3. Files fully open (no pawns of either colour): a, g, h — natural highways for the rooks and queen. Half-open for White: b, d, e.
The White king has 2 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
37. Qc8+ Ka7 38. Qd7+ Ka8 39. Qa4+ Kb8 40. Qxd4
Why it works
- Great move! queen to c8 keeps the pressure (+6.0).
- Spot on — queen to d7 (+6.2).
- Precise: queen to a4 is the top choice (+7.1).
- Great move! queen to d4 keeps the pressure (+7.2).
- You win a piece — the knight.
- If instead Ka7, then Qd7+ and you stay on top.
Move by move
- 37. Qc8+ — queen to c8 with check
- Ka7 — king to a7
- 38. Qd7+ — queen to d7 with check
- Ka8 — king to a8
- 39. Qa4+ — queen to a4 with check
- Kb8 — king to b8
- 40. Qxd4 — queen to d4 (capture)
Types in this puzzle
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.
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.
Relative pin
A piece shields a more valuable one behind it — moving it loses material.
In a relative pin the piece shields not its king but something valuable behind it, usually the queen. Moving is legal but costly, because the piece behind falls. Look for three units on one line: your long-range piece, a cheaper enemy piece, and an expensive one hiding behind. Beware the classic trap — a relatively pinned piece can still move with check or a bigger threat, so verify before you cash in.
About this position
These pieces come from starting position #667.
SP-667 · BastionGuard — The king starts one file off-centre, on c or f, with neither knight in a corner.
The king starts on c1, the rooks on a1 and d1, the queen on g1.
The king already stands on c1, so castling long moves only the rook, from a1 to d1.
A bishop starts in the corner on h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
One second-rank pawn starts with no defender at all: e2.
The setup belongs to the BastionGuard family; read right to left it becomes position 193.
The engine's main line opens with f4.
Morozov Balance Index: 13 of 100 — class D — largest edge. Engine evaluation of the starting position: +41 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #667Provenance
Mined from the project's engine self-play games.
Pack 013 · SP-667
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads