Attack on the uncastled king: bishop to b6 (a7)
c9-00621naming 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.
An opening trap from this Chess960 starting position.
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 780 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.
Early Chess960 traps punish natural but careless development. Look for a forcing move that exploits a piece the opponent has just placed on a poor square — a fork, a pin or a threat that wins material before either side is fully developed.
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 e1, rook b1 d1, bishop h1 a7, knight b3 e3, pawn a2 b2 c2 d2 e2 h2 g3 g5.
Black: king c8, queen e8, rook a8 d8, bishop g8 h8, knight b6 e6, pawn f5 d6 b7 c7 e7 h7.
16 white and 14 black pieces are on the board; the puzzle position arises after move 7.
The position in numbers
White are ahead by 2 points of material (39 against 37; 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 7, with 32 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 8 pawns, Black 6. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: f.
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
7. Bxb6 Qb5 8. Nd5 cxb6 9. Qf2
Why it works
- Great move! bishop to b6 keeps the pressure (+3.0).
- knight to d5 develops smoothly.
- A natural move: queen to f2.
- You reach a winning position (+3.1).
- If instead cxb6, then Qf2 and you stay on top.
Move by move
- 7. Bxb6 — bishop to b6 (capture)
Types in this puzzle
Corner bishop
A bishop born in the corner rakes the longest diagonal.
The corner bishop: in Chess960 a bishop often starts on a1 or h1, staring down the longest diagonal from birth. One pawn move and it fires across the entire board, hitting a rook or king in the far corner. In every starting position inspect the long diagonals: whose bishop sits in the corner, what blocks its path, which pawn move opens the line. The mistake is noticing the enemy corner bishop only after it has collected its loot.
Winning blow
Find the strike that wins material by force.
A winning blow is a forced material gain that does not fit a single textbook motif. The general tactical recipe applies: spot loose pieces, an awkwardly placed king, overloaded lines. Go through the forcing moves in order of violence — checks, captures, threats — because most combinations start with one of them. Do not judge by feel: calculate the concrete line until the outcome is beyond doubt.
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 #367.
SP-367 · BastionScout — A c- or f-file king with at least one knight out on the edge.
The king starts on c1, the rooks on b1 and d1, the queen on e1.
The king already stands on c1, so castling long moves only the rook, from b1 to d1.
A bishop starts in the corner on h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
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 304.
The engine's main line opens with f4.
Morozov Balance Index: 65 of 100 — class B — balanced. Engine evaluation of the starting position: +22 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #367Provenance
Mined from the project's engine self-play games.
Verified by Stockfish at depth 20+.
Solution forcedness confirmed (verified).
Pack 001 · SP-367
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