Attack on the uncastled king: bishop to b6 (g1·7)
c9-13512naming 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 920 ShuffleRating — for beginners taking their first steps in Chess960 tactics.
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 h1, rook a1 d1, bishop b1 g1, knight d2, pawn b2 e2 h2 c3 d3 g3 a4 f4.
Black: king c8, queen h8, rook a8 d8, bishop b6 g8, knight e8 f8, pawn a5 f5 c6 g6 b7 d7 e7 h7.
15 white and 16 black pieces are on the board; the puzzle position arises after move 11.
The position in numbers
Black are ahead by 3 points of material (36 against 39; 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 31 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 8 pawns, Black 8. No file is fully open, so the heavy pieces have to be pried in.
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. Bxb6 d6 12. Bxd8
Why it works
- Great move! bishop to b6 keeps the pressure (+2.9).
- Well found: bishop to d8 (+3.0).
- You win a piece — the rook.
- If instead d6, then Bxd8 and you win the rook.
Move by move
- 11. Bxb6 — bishop to b6 (capture)
- d6 — pawn to d6
- 12. Bxd8 — bishop to d8 (capture)
Types in this puzzle
Trapped piece
The attacked piece has no safe square — it is caught.
Trapping a piece means the attacked piece has no safe square left — it simply perishes. Do not chase it around; build a cage instead: cut off the escape squares with pawns and pieces first, and attack last. The typical victim has wandered deep into your camp or is stuck at the edge of the board, where its mobility is tiny. And always check the way home for your own raiders — or the trapped piece will be yours.
Only move
Everything else loses — find the only move that holds.
An only move is a position where everything loses except one single continuation. You cannot play "by hand" here: run through fundamentally different defenses — run away, block, trade, counterattack — and discard the ones that fail. The hallmark of these puzzles is that the obvious moves lose quickly while the solution often looks strange. First understand exactly what the threat is — then the one saving move reveals itself.
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.
About this position
These pieces come from starting position #956.
SP-956 · BastionGuard — A c- or f-file king and two knights on inner files (b–g).
The king starts on c1, the rooks on a1 and d1, the queen on h1.
The king already stands on c1, so castling long moves only the rook, from a1 to d1.
The bishops stand on b1 and g1; their long diagonals reach h7 and a7 once the c- and f-pawns step aside.
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 12.
The engine's main line opens with a4.
Morozov Balance Index: 65 of 100 — class B — balanced. Engine evaluation of the starting position: +22 centipawns for White (depth 48, 400 000 000 nodes).
Explore position #956Provenance
Mined from the project's engine self-play games.
Pack 004 · SP-956
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