Attack on the uncastled king: pawn to a4 (b3·3)
c9-02896naming 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 e1, queen c1, rook d1 f1, bishop b1, knight g1 h1, pawn a2 e2 g2 h2 b3 c4 f4 d5.
Black: king e8, queen a4, rook d8 f8, bishop a8 b8, knight h8, pawn h5 b6 f6 a7 c7 d7 e7 f7.
15 white and 15 black pieces are on the board; the puzzle position arises after move 7.
The position in numbers
Material is level — 36 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 7, with 35 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.
Black hold the bishop pair, an edge in open lines. The White king has 2 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
7. bxa4 Rg8 8. Kf2 Ng6 9. Nf3
Why it works
- Great move! pawn to a4 keeps the pressure (+7.0).
- king to f2 develops smoothly.
- A natural move: knight to f3.
- You win a piece — the queen.
- If instead Rg8, then g3 and you win the queen.
Move by move
- 7. bxa4 — pawn to a4 (capture)
Types in this puzzle
Hanging piece
A piece is left without protection — just take it.
A hanging piece is simply an unprotected piece you can take for free. It sounds primitive, yet most amateur games are decided exactly this way. Build the habit: before every move, sweep the board and note every undefended piece, yours and theirs. The classic mistake is hunting for a brilliant combination when all you need to do is bend down and pick up the gift.
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.
Early trap
In the first moves of a fresh setup a trap already snaps shut.
An early trap is a tactic that snaps shut within the first moves: an unfamiliar setup hides shots that classical openings never produce. Examine every starting position with fresh eyes — which pieces already aim at each other, what hangs after the first pawn moves. Moves that feel "safe" from classical habit can lose on the spot here. Chess960 has no opening theory; it has alertness from move one.
About this position
These pieces come from starting position #864.
SP-864 · ThroneScout — King on a central file (d/e) with a knight starting on the rim (a/h).
The king starts on e1, the rooks on d1 and f1, the queen on c1.
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.
The second rank carries 2 pawns with no defender at all: g2, h2.
The setup belongs to the ThroneScout family; read right to left it becomes position 95.
The engine's main line opens with Ng3, bringing the knight out to g3.
Morozov Balance Index: 5 of 100 — class D — largest edge. Engine evaluation of the starting position: +49 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #864Provenance
Mined from the project's engine self-play games.
Verified by Stockfish at depth 20+.
Solution forcedness confirmed (verified).
Pack 001 · SP-864
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