Winning blow: queen to a7 (a6)
c9-09824naming 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.
A fork made possible by the Chess960 piece placement.
Winning tactic: there is a move that gains a decisive advantage — find it.
Difficulty 1060 ShuffleRating — club-player level.
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.
A set-up fork needs one preparing move before the fork lands — a check that drives the king onto the forking square, or a capture that lines the targets up. Find the preparation first, then the fork it makes possible.
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 a6, rook d1 b3, bishop e3, pawn b2 c2 e2 f2 h2 g3 a4.
Black: king a8, queen a7, rook c8 f8, bishop c6, knight f7, pawn c5 f5 g5 e6 h6.
12 white and 11 black pieces are on the board; the puzzle position arises after move 22.
The position in numbers
Black are ahead by 1 points of material (29 against 30; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on c1, the black king on a8.
It is White to move on move 22, with 43 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 7 pawns, Black 5. Files fully open (no pawns of either colour): d — natural highways for the rooks and queen.
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
22. Qxa7+ Kxa7 23. Bxc5+ Ka8 24. Bxf8
Why it works
- Great move! queen to a7 keeps the pressure (+3.4).
- Well found: bishop to c5 (+3.5).
- Strong! bishop to f8 is the sharp choice (+3.7).
- You win a piece — the queen.
- If instead Kxa7, then Bxc5+ and you stay on top.
Move by move
- 22. Qxa7+ — queen to a7 (capture) with check
- Kxa7 — king to a7 (capture)
- 23. Bxc5+ — bishop to c5 (capture) with check
- Ka8 — king to a8
- 24. Bxf8 — bishop to f8 (capture)
Types in this puzzle
Setup fork
The random setup allows a fork that classical chess never sees.
A setup fork is a double attack that exists only because of the unusual starting squares — in classical chess these targets never stand side by side. Look for pairs of undefended pieces on your opponent's back rank and for squares from which a knight or pawn hits both at once. Such forks usually appear within the first moves, before the pieces disperse. In every new position, note right away which starting pieces are defended by no one.
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.
Simplification
Trade the heavy pieces and steer into a won endgame.
Simplification is how you convert an advantage: by trading queens and rooks you extinguish the counterplay and steer the game into a won endgame. The rule is simple — the side with extra material trades pieces but keeps pawns. Look for exchanges once the material is already won and your opponent is still rattling threats. The mistake is avoiding the queen trade and letting him muddy the water forever.
About this position
These pieces come from starting position #635.
SP-635 · BastionGuard — Off-centre king (c/f), no knight on the a- or h-file.
The king starts on c1, the rooks on a1 and f1, the queen on d1.
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: h2.
The setup belongs to the BastionGuard family; read right to left it becomes position 225.
The engine's main line opens with g4.
Morozov Balance Index: 69 of 100 — class B — balanced. Engine evaluation of the starting position: +21 centipawns for White (depth 43, 400 000 000 nodes).
Explore position #635Provenance
Mined from the project's engine self-play games.
Pack 006 · SP-635
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads