Attack on the uncastled king: rook to f7 (h7)
c9-02603naming 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.
Uncastled king: the enemy king is stuck in the centre — punish it before it castles.
Difficulty 850 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.
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 f1, queen b1, rook d1 h7, bishop a1 g2, knight c1 e1, pawn a2 b2 d2 e2 f2 c4 g6.
Black: king f8, queen c6, rook d8 g8, bishop a8 h8, knight b6 e8, pawn c5 a7 b7 d7 e7 f7.
15 white and 14 black pieces are on the board; the puzzle position arises after move 9.
The position in numbers
White are ahead by 1 points of material (38 against 37; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on f1, the black king on f8.
It is White to move on move 9, with 37 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 7 pawns, Black 6. Files fully open (no pawns of either colour): h — natural highways for the rooks and queen.
The White king has 1 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
9. Rxf7#
Why it works
- Great move! rook to f7 keeps the pressure (#).
- The line ends in a forced mate in 1.
Move by move
- 9. Rxf7# — rook to f7 (capture) and it is checkmate
Types in this puzzle
Epaulette mate
The king's own pieces flank it like epaulettes — mate comes head-on.
In the epaulette mate the king stands between two of its own pieces — most often rooks — like an officer wearing epaulettes. The side squares are blocked by friends, there is no retreat, and the queen mates head-on from directly in front of the king. The sign: a king on the edge rank with both neighboring squares on that rank occupied by its own pieces. Remember, extra defenders crowding the king can be deadlier than no defenders at all.
King in the center
The king starts in the middle — and the storm reaches it first.
King in the center: in Chess960 the monarch may start on the d- or e-file, right in the line of fire, and the attack can reach him before he ever castles. The signs: the enemy king still sits on its central starting square while the files toward it are opening. Play to rip the center open — a pawn sacrifice usually pays off here. And if it is your king in the middle, castle at the very first opportunity.
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.
About this position
These pieces come from starting position #99.
SP-99 · BastionGuard — King shifted to c or f, knights kept clear of the edges — 168 positions in all.
The king starts on f1, the rooks on d1 and g1, the queen on b1.
Castling short simply swaps the two pieces: the king on f1 and the rook on g1 trade places.
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: h2.
The setup belongs to the BastionGuard family; read right to left it becomes position 851.
The engine's main line opens with b4.
Morozov Balance Index: 80 of 100 — class A — most balanced. Engine evaluation of the starting position: +17 centipawns for White (depth 46, 400 000 000 nodes).
Explore position #99Provenance
Mined from the project's engine self-play games.
Verified by Stockfish at depth 20+.
Solution forcedness confirmed (verified).
Pack 004 · SP-99
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads