Attack on the uncastled king: bishop to c6 (b7·4)
c9-17206naming 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 1150 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 e2, queen c7, rook d1, bishop c1 b7, knight d5, pawn b2 h2 d3 e3 b5.
Black: king e8, queen b3, rook f1 d8, bishop g5, knight e5, pawn g4 c5 d6 g6 h7.
11 white and 11 black pieces are on the board; the puzzle position arises after move 23.
The position in numbers
Black are ahead by 2 points of material (28 against 30; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on e2, the black king on e8.
It is White to move on move 23, with 34 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 5 pawns, Black 5. Files fully open (no pawns of either colour): a, f — natural highways for the rooks and queen. Half-open for White: c, g.
White hold the bishop pair, an edge in open lines. 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
23. Bc6+ Kf8 24. Rxf1+
Why it works
- Great move! bishop to c6 keeps the pressure (+3.4).
- Well found: rook to f1 (+3.9).
- You win a piece — the rook.
- If instead Kf8, then Rxf1+ and you win the rook.
Move by move
- 23. Bc6+ — bishop to c6 with check
- Kf8 — king to f8
- 24. Rxf1+ — rook to f1 (capture) with check
Types in this puzzle
Check chase
Every move is a check — the king is chased into losing ground.
In a check chase every one of your moves is a check, so the opponent never gets a free second. The king is herded across the board until it loses a piece or walks into a decisive blow. Such lines are the easiest to calculate: each check allows only a handful of replies, so try them all. Make it a habit to start calculating any sharp position with the checks — they are the most forcing moves on the board.
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 defense
Mate is threatened — parry it and stay on top.
Mate defense: your opponent is one move from mating you — but it is your turn, and that changes everything. Find the defense that kills the mating threat while keeping your advantage: often a check or a counter-threat that leaves no time for the mate. First name the exact square where the mate would land — otherwise you are defending blind. The mistake is playing a "defensive" move that does not actually remove the threat.
About this position
These pieces come from starting position #87.
SP-87 · ThroneScout — Centre-file king, rim knight: 204 of the 960 positions share this pattern.
The king starts on e1, the rooks on d1 and f1, the queen on g1.
The kingside rook already stands on f1, so castling short moves only the king, from e1 to g1.
A bishop starts in the corner on h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
One second-rank pawn starts with no defender at all: a2.
The setup belongs to the ThroneScout family; read right to left it becomes position 866.
The engine's main line opens with f4.
Morozov Balance Index: 55 of 100 — class B — balanced. Engine evaluation of the starting position: +25 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #87Provenance
Mined from the project's engine self-play games.
Pack 007 · SP-87
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads