Winning blow: queen to d8 (d7·5)
c9-26748naming 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 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.
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 f1, queen d7, rook h1, bishop f3, knight e1, pawn a2 c2 f2 g2 h4 e5.
Black: king b8, queen b1, rook h8, bishop c5, knight e8, pawn a4 c4 e6 f7 g7 h7.
11 white and 11 black pieces are on the board; the puzzle position arises after move 22.
The position in numbers
Material is level — 26 points of pieces on each side (pawn = 1, knight and bishop = 3, rook = 5, queen = 9).
The white king stands on f1, the black king on b8.
It is White to move on move 22, with 37 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 6. Files fully open (no pawns of either colour): b, 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. Qd8+ Ka7 23. Qa8+ Kb6 24. Qb7+ Ka5 25. Qxb1
Why it works
- Great move! queen to d8 keeps the pressure (+7.0).
- Spot on — queen to a8 (+7.5).
- Precise: queen to b7 is the top choice (+7.5).
- Best move. queen to b1 is exactly what the engine plays (+7.6).
- You win a piece — the queen.
- If instead Ka7, then Qa8+ and you stay on top.
Move by move
- 22. Qd8+ — queen to d8 with check
- Ka7 — king to a7
- 23. Qa8+ — queen to a8 with check
- Kb6 — king to b6
- 24. Qb7+ — queen to b7 with check
- Ka5 — king to a5
- 25. Qxb1 — queen to b1 (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.
Skewer
A line attack forces the valuable piece to move, exposing the one behind it.
A skewer is a pin turned inside out: the valuable piece stands in front and something cheaper hides behind it. The big piece must step aside, and you collect the one that was sheltering in its shadow. Scan for the enemy king or queen sharing a file, rank or diagonal with another enemy piece. The deadliest version comes with check — the king moves, the rook behind it dies.
About this position
These pieces come from starting position #678.
SP-678 · ThroneGuard — King on a central file (d/e) with both knights on inner files — the classic-type setup.
The king starts on d1, the rooks on b1 and h1, the queen on a1.
Castling ends where it always does: king to g1 and rook to f1 on the short side, king to c1 and rook to d1 on the long one.
The bishops stand on c1 and f1; their long diagonals reach h6 and a6 once the d- and e-pawns step aside.
One second-rank pawn starts with no defender at all: f2.
The setup belongs to the ThroneGuard family; read right to left it becomes position 470.
The engine's main line opens with e4, putting a pawn straight into the centre.
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 #678Provenance
Mined from the project's engine self-play games.
Pack 013 · SP-678
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