Attack on the uncastled king: queen to a6 (a5)
c9-09713naming 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 970 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 a5, rook d1 f1, bishop a3, knight h1 f3, pawn a2 d2 f2 g2 h2 b3 c3 e3.
Black: king e8, queen a8, rook f8, bishop d6 d7, knight h5 f6, pawn d4 b6 a7 e7 f7 h7.
15 white and 13 black pieces are on the board; the puzzle position arises after move 12.
The position in numbers
White are ahead by 4 points of material (36 against 32; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on e1, the black king on e8.
It is White to move on move 12, with 40 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.
Black hold the bishop pair, an edge in open lines. 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
12. Qa6 Bc8 13. Qc4 Be6 14. Qxd4
Why it works
- Great move! queen to a6 keeps the pressure (+3.0).
- queen to c4 develops smoothly.
- Precise: queen to d4 is the top choice (+3.2).
- You reach a winning position (+3.2).
- If instead Bc8, then Qc4 and you stay on top.
Move by move
- 12. Qa6 — queen to a6
Types in this puzzle
Quiet move
No check, no capture — yet this modest move decides the game.
A quiet move gives no check and takes nothing — yet it decides the game by creating an unstoppable threat or stealing the king's last square. This is the hardest class of moves: the eye hunts for loud blows while a modest shift does the winning. The clue: every forcing try runs into a defense, so seek the move that strengthens the threat or takes squares away. Train yourself to ask: what if I neither capture nor check, but quietly improve?
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 #868.
SP-868 · ThroneScout — A knight starts on the edge (a/h) and the king sits centrally on d or e; the mirror twin stays in this family too.
The king starts on e1, the rooks on d1 and f1, the queen on a1.
The kingside rook already stands on f1, so castling short moves only the king, from e1 to g1.
The bishops stand on b1 and c1; their long diagonals reach h7 and h6 once the c- and d-pawns step aside.
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 94.
The engine's main line opens with Ng3, bringing the knight out to g3.
Morozov Balance Index: 0 of 100 — class D — largest edge. Engine evaluation of the starting position: +75 centipawns for White (depth 43, 400 000 000 nodes).
In 50 self-play games White scored 59.0% (95% CI 45.2–71.5%).
Explore position #868Provenance
Mined from the project's engine self-play games.
Pack 005 · SP-868
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