Attack on the uncastled king: bishop to f8 (g7·2)
c9-25870naming tag (square·N)The tactical motive
Chess960 twist: use the unusual starting setup of the pieces.
Mate in 3: a forced sequence that ends in checkmate.
Uncastled king: the enemy king is stuck in the centre — punish it before it castles.
Difficulty 1630 ShuffleRating — for advanced tacticians.
White to move — find the best continuation
Position on the board
White: king g1, queen g3, rook h1, bishop f1 g7, knight e3 f5, pawn g2 f3 b4 e4 h4.
Black: king g8, queen b1, rook c2 h8, bishop a8 f8, pawn b5 d5 h5 a6.
12 white and 10 black pieces are on the board; the puzzle position arises after move 17.
Solution & explanation
Main line
17. Bxf8+ Kf7 18. Qg7+ Ke8 19. Qe7#
Why it works
- Great move! bishop to f8 keeps the pressure (#2).
- Spot on — queen to g7 (#1).
- Precise: queen to e7 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Kf7, then Qg7+ and you win the bishop.
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.
Mate in 3
A forced checkmate in three moves.
Mate in three is a forced staircase: each of your moves narrows the opponent's choices, and the third one ends the game. Look for the start among checks and sacrifices — quiet first moves are rare in mating problems, but deliciously sneaky. Keep the tree in your head: every defense gets its own branch. Do not stop calculating after move two — see the final mating picture with your own eyes.
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 #434.
SP-434 · RampartGuard — A b- or g-file king and two knights on inner files (b–g).
The king starts on g1, the rooks on b1 and h1, the queen on e1.
The king already stands on its castled square, so castling short moves only the rook, from h1 to f1.
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: c2.
The setup belongs to the RampartGuard family; read right to left it becomes position 711.
The engine's main line opens with h4.
Morozov Balance Index: 65 of 100 — class B — balanced. Engine evaluation of the starting position: +22 centipawns for White (depth 48, 400 000 000 nodes).
Explore position #434Provenance
Mined from the project's engine self-play games.
Pack 012 · SP-434
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