Attack on the uncastled king: queen to g8 (h7)
c9-06572naming 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.
Mate in 1: find the move after which the enemy king has no escape.
A fork made possible by the Chess960 piece placement.
Uncastled king: the enemy king is stuck in the centre — punish it before it castles.
Difficulty 620 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.
A mate in one hides among forcing checks. Run through every check you can give: does it cover all the king's escape squares, is the checking piece safe or supported, and can nothing block or capture it? If yes, that is the mate.
A set-up fork needs one preparing move before the fork lands — a check that drives the king onto the forking square, or a capture that lines the targets up. Find the preparation first, then the fork it makes possible.
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.
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 h7, rook c1 h1, bishop d1 h8, knight e3 f3, pawn a2 d2 e2 f2 h2 c3 g3 b4.
Black: king e8, queen b8, rook c8, bishop b6 a8, knight d5 g8, pawn b5 c5 f6 a7 d7 e7.
16 white and 13 black pieces are on the board; the puzzle position arises after move 9.
The position in numbers
White are ahead by 7 points of material (39 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 9, with 47 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.
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
9. Qxg8#
Why it works
- Great move! queen to g8 keeps the pressure (#).
- The line ends in a forced mate in 1.
Move by move
- 9. Qxg8# — queen to g8 (capture) and it is checkmate
Types in this puzzle
Mate in 1
Checkmate in a single move — find it.
Mate in one: the combination is over, only the final precise shot remains. The method is simple — list every check you have and test the three escapes against each: king moves, blocks, and capturing the checker. If none of them works, it is mate. The classic blunder is falling in love with the first check you see and missing the one escape hatch.
Setup fork
The random setup allows a fork that classical chess never sees.
A setup fork is a double attack that exists only because of the unusual starting squares — in classical chess these targets never stand side by side. Look for pairs of undefended pieces on your opponent's back rank and for squares from which a knight or pawn hits both at once. Such forks usually appear within the first moves, before the pieces disperse. In every new position, note right away which starting pieces are defended by no one.
Royal fork
A fork with check: the king must move, and the second piece is lost.
A royal fork is a fork with check — one of the two targets is the king itself. The check must be answered first, so nobody is left to rescue the second piece. Look for squares where your piece gives check and simultaneously attacks an undefended queen or rook. It is the most reliable fork of all, because your opponent literally has no choice.
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 001 · SP-673
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