Attack on the uncastled king: bishop to a6 (d3·6)
c9-21904naming 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.
Uncastled king: the enemy king is stuck in the centre — punish it before it castles.
Winning tactic: there is a move that gains a decisive advantage — find it.
Difficulty 1200 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.
An uncastled king in the centre is a standing target. Look for ways to open the central files and diagonals against it with checks and threats before it can shelter — every tempo the king spends in the middle is a chance for a combination.
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 g1, rook b1 d1, bishop b2 d3, knight g3, pawn c2 g2 h2 b3 f3 a4 d4.
Black: king c8, queen g8, rook b8 d8, bishop a3 a8, knight e8, pawn e4 h5 b6 e6 g6 a7 c7 f7.
14 white and 15 black pieces are on the board; the puzzle position arises after move 11.
The position in numbers
Black are ahead by 1 points of material (35 against 36; 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 c8.
It is White to move on move 11, with 32 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 7 pawns, Black 8. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: e.
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
11. Ba6+ Bb7 12. Bxb7+ Rxb7 13. Bxa3 exf3 14. gxf3
Why it works
- Great move! bishop to a6 keeps the pressure (+4.6).
- Well found: bishop to b7 (+4.6).
- Strong! bishop to a3 is the sharp choice (+4.7).
- Best move. pawn to f3 is exactly what the engine plays (+4.6).
- You win a piece — the bishop.
- If instead Bb7, then Bxb7+ and you win the bishop.
Move by move
- 11. Ba6+ — bishop to a6 with check
- Bb7 — bishop to b7
- 12. Bxb7+ — bishop to b7 (capture) with check
- Rxb7 — rook to b7 (capture)
- 13. Bxa3 — bishop to a3 (capture)
- exf3 — pawn to f3 (capture)
- 14. gxf3 — pawn to f3 (capture)
Types in this puzzle
Win the pinned piece
The pinned piece cannot run — attack it again and win it.
A pinned piece cannot flee, which means you can win it outright by attacking it one more time. Count attackers against defenders: if you outnumber them, the piece is yours. The best extra attacker is a pawn, since it costs less than anything it might capture. Do not rush the capture — build up the pressure first, then harvest.
Uncastled king
The king lingered in the middle — punish the delay.
Punishing the uncastled king: your opponent delayed castling, and now his king is stuck on its starting square under fire. In Chess960 this is deadlier than in classical chess — the king may start in the center or near the edge, and the familiar defensive setups simply do not apply. The signs: the victim still holds castling rights, and the files toward his king are half-open. Open lines before the king manages to hide.
Development punish
Half the army still asleep — the attack breaks through.
Punishing lazy development: half of your opponent's army is asleep on its starting squares, which means you outnumber him where the fight is. Count not the pieces on the board but the pieces in play — if five or more of his pieces have never moved, look for a forcing attack. The sign is a development lead plus open lines toward his king. Strike immediately: give him two quiet moves and the advantage evaporates.
About this position
These pieces come from starting position #930.
SP-930 · BastionScout — King off-centre on c or f with a knight starting on the rim (a/h).
The king starts on c1, the rooks on b1 and d1, the queen on g1.
The king already stands on c1, so castling long moves only the rook, from b1 to d1.
A bishop starts in the corner on a1: it has a single diagonal, which the b-pawn unlocks, running out to h8.
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 23.
The engine's main line opens with f3.
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 #930Provenance
Mined from the project's engine self-play games.
Pack 008 · SP-930
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads