Attack on the uncastled king: queen to b4 (b1)
c9-05894naming 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 f1, queen b1, rook d1 h1, bishop a1 c2, knight e3, pawn a2 e2 f2 f3 d4 h4 c5.
Black: king e8, queen b8, rook d8 h8, bishop c7 a8, knight b4, pawn b5 c6 e6 h6 a7 f7 g7.
14 white and 14 black pieces are on the board; the puzzle position arises after move 15.
The position in numbers
Material is level — 35 points of pieces on each side (pawn = 1, knight and bishop = 3, rook = 5, queen = 9).
The white king stands on f1, the black king on e8.
It is White to move on move 15, with 33 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: b, g.
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. Qxb4 a5 16. Qb2 Ke7 17. Bd3
Why it works
- Great move! queen to b4 keeps the pressure (+5.2).
- queen to b2 develops smoothly.
- Precise: bishop to d3 is the top choice (+4.9).
- You win a piece — the knight.
- If instead a5, then Qb2 and you win the knight.
Move by move
- 15. Qxb4 — queen to b4 (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.
About this position
These pieces come from starting position #673.
SP-673 · ThroneGuard — A central king (d or e) and two knights tucked onto inner files: the family that holds the standard array, SP-518.
The king starts on e1, the rooks on c1 and h1, the queen on b1.
Castling ends where it always does: king to g1 and rook to f1 on the short side, king to c1 and rook to d1 on the long one.
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: g2.
The setup belongs to the ThroneGuard family; read right to left it becomes position 475.
The engine's main line opens with b4.
Morozov Balance Index: 91 of 100 — class A — most balanced. Engine evaluation of the starting position: +13 centipawns for White (depth 48, 400 000 000 nodes).
Explore position #673Provenance
Mined from the project's engine self-play games.
Verified by Stockfish at depth 20+.
Solution forcedness confirmed (verified).
Pack 002 · SP-673
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