Attack on the uncastled king: bishop to g6 (f5·3)
c9-17742naming 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 3: a forced sequence that ends in checkmate.
Uncastled king: the enemy king is stuck in the centre — punish it before it castles.
Difficulty 1860 ShuffleRating — for advanced tacticians.
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.
In a mate in three every move must be forcing; the defender should never get a free tempo. Find the check or threat that herds the king, calculate the single defence to each, and confirm the net closes on the third move.
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 b1, rook d1 g1, bishop a1 f5, knight f2 d4, pawn a2 e3 g3 h4.
Black: king e8, queen b8, rook d8 g8, bishop a8 f8, knight c4 e7, pawn b4 d5 b6 h6 a7 d7 g7.
12 white and 15 black pieces are on the board; the puzzle position arises after move 14.
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 e1, the black king on e8.
It is White to move on move 14, with 45 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 4 pawns, Black 7. Files fully open (no pawns of either colour): c, f — natural highways for the rooks and queen. Half-open for White: b, d.
The White king has 4 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
14. Bg6+ Nxg6 15. Qxg6+ Ke7 16. Nf5#
Why it works
- Great move! bishop to g6 keeps the pressure (#2).
- Well found: queen to g6 (#1).
- Strong! knight to f5 is the sharp choice (#).
- The line ends in a forced mate in 3.
- If instead Nxg6, then Qxg6+ and you stay on top.
Move by move
- 14. Bg6+ — bishop to g6 with check
- Nxg6 — knight to g6 (capture)
- 15. Qxg6+ — queen to g6 (capture) with check
- Ke7 — king to e7
- 16. Nf5# — knight to f5 and it is checkmate
Types in this puzzle
Knight mate
The knight lands the killing blow from its unique angle.
In a knight mate the final blow comes from the knight — the only piece whose check can never be blocked. That makes it lethal against a cramped king: only a king move or capturing the knight itself can help. The sign: the squares around the king are occupied or covered, and there is a hop from which the knight checks while staying untouchable. Bring the knight over early — it is slower than the long-range pieces, but its strike cannot be parried.
Only move
Everything else loses — find the only move that holds.
An only move is a position where everything loses except one single continuation. You cannot play "by hand" here: run through fundamentally different defenses — run away, block, trade, counterattack — and discard the ones that fail. The hallmark of these puzzles is that the obvious moves lose quickly while the solution often looks strange. First understand exactly what the threat is — then the one saving move reveals itself.
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.
About this position
These pieces come from starting position #290.
SP-290 · ThroneScout — The king starts on d or e while at least one knight begins in a corner.
The king starts on e1, the rooks on d1 and g1, the queen on b1.
The queenside rook already stands on d1, so castling long moves only the king, from e1 to c1.
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 ThroneScout family; read right to left it becomes position 375.
The engine's main line opens with c4.
Morozov Balance Index: 16 of 100 — class D — largest edge. Engine evaluation of the starting position: +39 centipawns for White (depth 46, 400 000 000 nodes).
Explore position #290Provenance
Mined from the project's engine self-play games.
Pack 013 · SP-290
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