Attack on the uncastled king: bishop to f3 (e2·5)
c9-12950naming 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.
Uncastled king: the enemy king is stuck in the centre — punish it before it castles.
Winning tactic: there is a move that gains a decisive advantage — find it.
Difficulty 1010 ShuffleRating — club-player level.
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.
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.
This position hides a concrete tactic that wins material or mates. Start with the most forcing candidate moves — checks, captures and threats — and calculate each to a clear end before choosing; the winning line is usually the one the opponent cannot meet.
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 g2, rook c1 g1, bishop e1 e2, knight b1 b3, pawn a2 b2 h2 c3 d3 e3.
Black: king f8, queen h6, rook c8 g8, bishop c6 d8, knight b8, pawn f3 b4 c5 f5 g5 d6 a7 e7.
14 white and 15 black pieces are on the board; the puzzle position arises after move 13.
The position in numbers
White are ahead by 1 points of material (37 against 36; 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 13, with 33 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 8. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: f, g.
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
13. Bxf3 g4 14. Bxc6 Nxc6 15. Ke2
Why it works
- Great move! bishop to f3 keeps the pressure (+2.3).
- Well found: bishop to c6 (+2.4).
- A natural move: king to e2.
- You reach a winning position (+2.3).
- If instead g4, then Bxc6 and you win the bishop.
Move by move
- 13. Bxf3 — bishop to f3 (capture)
Types in this puzzle
Winning blow
Find the strike that wins material by force.
A winning blow is a forced material gain that does not fit a single textbook motif. The general tactical recipe applies: spot loose pieces, an awkwardly placed king, overloaded lines. Go through the forcing moves in order of violence — checks, captures, threats — because most combinations start with one of them. Do not judge by feel: calculate the concrete line until the outcome is beyond doubt.
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.
Development punish
Half the army still asleep — the attack breaks through.
Punishing lazy development: half of your opponent's army is asleep on its starting squares, which means you outnumber him where the fight is. Count not the pieces on the board but the pieces in play — if five or more of his pieces have never moved, look for a forcing attack. The sign is a development lead plus open lines toward his king. Strike immediately: give him two quiet moves and the advantage evaporates.
About this position
These pieces come from starting position #89.
SP-89 · BastionScout — King shifted to c or f, with a knight committed to the corner from move one.
The king starts on f1, the rooks on c1 and g1, the queen on h1.
Castling short simply swaps the two pieces: the king on f1 and the rook on g1 trade places.
The bishops stand on d1 and e1; their long diagonals reach h5 and a5 once the e- and d-pawns step aside.
The second rank carries 2 pawns with no defender at all: a2, b2.
The setup belongs to the BastionScout family; read right to left it becomes position 873.
The engine's main line opens with b4.
Morozov Balance Index: 61 of 100 — class B — balanced. Engine evaluation of the starting position: +23 centipawns for White (depth 42, 400 000 000 nodes).
Explore position #89Provenance
Mined from the project's engine self-play games.
Pack 006 · SP-89
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