Attack on the uncastled king: bishop to b3 (d1·2)
c9-09116naming 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 1110 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 g1, queen e1, rook f1 h1, bishop d1 b2, knight b1 c1, pawn a2 f2 g2 d3 e4 h4.
Black: king g8, queen g6, rook f8 h8, bishop c7 a8, knight c4 b8, pawn c5 h5 f6 a7 d7 e7 g7.
14 white and 15 black pieces are on the board; the puzzle position arises after move 10.
The position in numbers
Black are ahead by 1 points of material (37 against 38; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on g1, the black king on g8.
It is White to move on move 10, with 35 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 7. Files fully open (no pawns of either colour): b — natural highways for the rooks and queen. Half-open for White: c.
The White king has 0 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
10. Bb3 d5 11. dxc4
Why it works
- Great move! bishop to b3 keeps the pressure (+2.7).
- Well found: pawn to c4 (+2.6).
- You win a piece — the knight.
- If instead d5, then dxc4 and you win the knight.
Move by move
- 10. Bb3 — bishop to b3
- d5 — pawn to d5
- 11. dxc4 — pawn to c4 (capture)
Types in this puzzle
Absolute pin
A piece is pinned against its king — it cannot legally move.
An absolute pin freezes a piece on the line between its own king and your long-range attacker: moving it is simply illegal. The pattern is three units on one straight line — your bishop, rook or queen, an enemy piece, and the enemy king behind it. A pinned piece neither attacks nor defends anything: treat it as if it were off the board. Pile up on it, ideally with a pawn, because running away is against the rules.
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 #33.
SP-33 · RampartGuard — King pushed to the b- or g-file, knights off the edges — 144 positions here.
The king starts on g1, the rooks on f1 and h1, the queen on e1.
The king already stands on its castled square, so castling short moves only the rook, from h1 to f1.
A bishop starts in the corner on a1: it has a single diagonal, which the b-pawn unlocks, running out to h8.
The pawn on g2 is defended by the king alone — the same soft spot f2 is in the classical setup.
The setup belongs to the RampartGuard family; read right to left it becomes position 923.
The engine's main line opens with h4.
Morozov Balance Index: 16 of 100 — class D — largest edge. Engine evaluation of the starting position: +39 centipawns for White (depth 43, 400 000 000 nodes).
Explore position #33Provenance
Mined from the project's engine self-play games.
Pack 007 · SP-33
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads