Attack on the uncastled king: queen to f7 (f2·2)
c9-00604naming 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 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.
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 g1, queen f2, rook a1 f1, bishop e1 a2, knight c1 e3, pawn g2 d4 e4 h6.
Black: king g8, queen d5, rook a8 h8, bishop a4 b8, knight b6 e6, pawn c2 g6 a7 b7 e7 f7 h7.
12 white and 15 black pieces are on the board; the puzzle position arises after move 15.
The position in numbers
Black are ahead by 3 points of material (35 against 38; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on g1, the black king on g8.
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 4 pawns, Black 7. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: a, b, c, f.
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
15. Qxf7#
Why it works
- Great move! queen to f7 keeps the pressure (#).
- The line ends in a forced mate in 1.
Move by move
- 15. Qxf7# — queen to f7 (capture) and it is checkmate
Types in this puzzle
Supported queen mate
The queen delivers mate face to face, protected by a friend.
The supported queen mate is the most common pattern of all: the queen lands next to the king and mates because a friendly piece or pawn protects her. The king is helpless — capturing is impossible, and the queen covers every neighboring square herself. Hunt for a protected square beside the enemy king: a knight, bishop or pawn eyeing it turns her invasion into mate. Verify one thing — that the square really is defended, or the king eats her.
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.
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 #440.
SP-440 · RampartGuard — A b- or g-file king and two knights on inner files (b–g).
The king starts on g1, the rooks on a1 and h1, the queen on f1.
The king already stands on its castled square, so castling short moves only the rook, from h1 to f1.
The bishops stand on b1 and e1; their long diagonals reach h7 and a5 once the c- and d-pawns step aside.
Every pawn on the second rank is defended from the very first move.
The setup belongs to the RampartGuard family; read right to left it becomes position 717.
The engine's main line opens with h4.
Morozov Balance Index: 28 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +33 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #440Provenance
Mined from the project's engine self-play games.
Verified by Stockfish at depth 20+.
Solution forcedness confirmed (verified).
Pack 004 · SP-440
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