Attack on the uncastled king: bishop to b2 (a1·11)
c9-06568naming 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 1560 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 f2, queen h1, rook c1 g4, bishop a1 f1, knight b1 f3, pawn a2 d3 c4 e4 h4.
Black: king d8, queen h8, rook c8 g8, bishop b2 a8, knight b8, pawn g5 b6 a7 c7 d7 e7 f7.
13 white and 14 black pieces are on the board; the puzzle position arises after move 10.
The position in numbers
White are ahead by 1 points of material (36 against 35; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on f2, the black king on d8.
It is White to move on move 10, with 40 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 5 pawns, Black 7. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: b, f, g.
The White king has 6 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
10. Bxb2 Qxb2+ 11. Be2 f5 12. Rxg5
Why it works
- Best move. bishop to b2 is exactly what the engine plays (+2.2).
- Well found: bishop to e2 (+2.1).
- Precise: rook to g5 is the top choice (+2.5).
- You reach a winning position (+2.5).
- If instead Qxb2+, then Be2 and you stay on top.
Move by move
- 10. Bxb2 — bishop to b2 (capture)
- Qxb2+ — queen to b2 (capture) with check
- 11. Be2 — bishop to e2
- f5 — pawn to f5
- 12. Rxg5 — rook to g5 (capture)
Types in this puzzle
Corner bishop
A bishop born in the corner rakes the longest diagonal.
The corner bishop: in Chess960 a bishop often starts on a1 or h1, staring down the longest diagonal from birth. One pawn move and it fires across the entire board, hitting a rook or king in the far corner. In every starting position inspect the long diagonals: whose bishop sits in the corner, what blocks its path, which pawn move opens the line. The mistake is noticing the enemy corner bishop only after it has collected its loot.
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.
About this position
These pieces come from starting position #274.
SP-274 · ThroneGuard — A centre-file king with no knight on the edge; a position and its mirror twin always share this family.
The king starts on d1, the rooks on c1 and g1, the queen on h1.
Castling long simply swaps the two pieces: the king on d1 and the rook on c1 trade places.
A bishop starts in the corner on a1: it has a single diagonal, which the b-pawn unlocks, running out to h8.
The second rank carries 2 pawns with no defender at all: a2, f2.
The setup belongs to the ThroneGuard family; read right to left it becomes position 583.
The engine's main line opens with g4.
Morozov Balance Index: 55 of 100 — class B — balanced. Engine evaluation of the starting position: +25 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #274Provenance
Mined from the project's engine self-play games.
Verified by Stockfish at depth 20+.
Solution forcedness confirmed (verified).
Pack 011 · SP-274
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads