Attack on the uncastled king: pawn to c6 (b5·11)
c9-04426naming 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 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.
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 e1, queen f4, rook b1 f1, bishop c2, knight a3, pawn a2 d2 f2 g2 f3 h4 b5.
Black: king e8, queen h8, rook c8 f8, knight c6 b8, pawn h5 e6 g6 a7 c7 d7 f7.
13 white and 13 black pieces are on the board; the puzzle position arises after move 15.
The position in numbers
Material is level — 32 points of pieces on each side (pawn = 1, knight and bishop = 3, rook = 5, queen = 9).
The white king stands on e1, the black king on e8.
It is White to move on move 15, with 42 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 7 pawns, Black 7. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: c, e.
The White king has 3 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
15. bxc6 Nxc6 16. O-O Qd4 17. Qg5
Why it works
- Great move! pawn to c6 keeps the pressure (+4.1).
- king to g1 develops smoothly.
- A natural move: queen to g5.
- You reach a winning position (+4.2).
- If instead Nxc6, then O-O and you stay on top.
Move by move
- 15. bxc6 — pawn to c6 (capture)
Types in this puzzle
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 #369.
SP-369 · ThroneGuard — Both knights start on inner files (b–g) while the king sits centrally on d or e — one of 204 positions filed here.
The king starts on e1, the rooks on c1 and f1, the queen on h1.
The kingside rook already stands on f1, so castling short moves only the king, from e1 to g1.
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 ThroneGuard family; read right to left it becomes position 299.
The engine's main line opens with g4.
Morozov Balance Index: 61 of 100 — class B — balanced. Engine evaluation of the starting position: +23 centipawns for White (depth 49, 400 000 000 nodes).
Explore position #369Provenance
Mined from the project's engine self-play games.
Verified by Stockfish at depth 20+.
Solution forcedness confirmed (verified).
Pack 002 · SP-369
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