Winning blow: king to b3 (a2·5)
c9-25725naming 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 1390 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.
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 a2, queen a5, rook c3, knight b4, pawn b2 h2 f4 e5 c6.
Black: king c8, queen b1, rook g1, bishop f8, pawn f5 e6 d7 h7.
9 white and 8 black pieces are on the board; the puzzle position arises after move 33.
The position in numbers
White are ahead by 1 points of material (22 against 21; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on a2, the black king on c8.
It is White to move on move 33, with 2 legal replies to weigh — only the line that keeps the advantage solves the puzzle. White are in check right now, so every reply must answer the check.
White keeps 5 pawns, Black 4. Files fully open (no pawns of either colour): a, g — natural highways for the rooks and queen. Half-open for White: d.
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
33. Kb3 Qd1+ 34. Rc2 dxc6 35. Qa8+ Kd7 36. Qxf8
Why it works
- Great move! king to b3 keeps the pressure (+4.8).
- rook to c2 develops smoothly.
- Strong! queen to a8 is the sharp choice (+5.7).
- Great move! queen to f8 keeps the pressure (+5.7).
- You win decisive material (+5.7).
- If instead Qd1+, then Rc2 and you stay on top.
Move by move
- 33. Kb3 — king to b3
- Qd1+ — queen to d1 with check
- 34. Rc2 — rook to c2
- dxc6 — pawn to c6 (capture)
- 35. Qa8+ — queen to a8 with check
- Kd7 — king to d7
- 36. Qxf8 — queen to f8 (capture)
Types in this puzzle
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 #254.
SP-254 · BastionScout — The king starts one file off-centre, on c or f, and a knight begins in a corner.
The king starts on c1, the rooks on b1 and h1, the queen on d1.
The king already stands on c1, so castling long moves only the rook, from b1 to d1.
The bishops stand on f1 and g1; their long diagonals reach a6 and a7 once the e- and f-pawns step aside.
One second-rank pawn starts with no defender at all: a2.
The setup belongs to the BastionScout family; read right to left it becomes position 612.
The engine's main line opens with f4.
Morozov Balance Index: 5 of 100 — class D — largest edge. Engine evaluation of the starting position: +49 centipawns for White (depth 47, 400 000 000 nodes).
Explore position #254Provenance
Mined from the project's engine self-play games.
Pack 010 · SP-254
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