Attack on the uncastled king: bishop to b4 (e1·10)
c9-27456naming 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 g1, queen c4, rook a1 g2 a8, bishop b1 e1, knight b3, pawn a2 b2 e2 f2 f3 d5.
Black: king f8, queen d8, rook g8, bishop h3 b8, pawn g3 e6 a7 f7 g7.
14 white and 10 black pieces are on the board; the puzzle position arises after move 17.
The position in numbers
White are ahead by 14 points of material (39 against 25; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on g1, the black king on f8.
It is White to move on move 17, with 46 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 5. Files fully open (no pawns of either colour): c, h — natural highways for the rooks and queen. Half-open for White: 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
17. Bb4+ Qd6 18. Bxd6+ Ke8 19. Qc8#
Why it works
- Great move! bishop to b4 keeps the pressure (#2).
- Spot on — bishop to d6 (#1).
- Precise: queen to c8 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Qd6, then Bxd6+ and you win the queen.
Move by move
- 17. Bb4+ — bishop to b4 with check
- Qd6 — queen to d6
- 18. Bxd6+ — bishop to d6 (capture) with check
- Ke8 — king to e8
- 19. Qc8# — queen to c8 and it is checkmate
Types in this puzzle
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.
Royal fork
A fork with check: the king must move, and the second piece is lost.
A royal fork is a fork with check — one of the two targets is the king itself. The check must be answered first, so nobody is left to rescue the second piece. Look for squares where your piece gives check and simultaneously attacks an undefended queen or rook. It is the most reliable fork of all, because your opponent literally has no choice.
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 #616.
SP-616 · BastionScout — A knight on the a- or h-file, king on c or f — the mirror twin lands here as well.
The king starts on f1, the rooks on a1 and g1, the queen on d1.
Castling short simply swaps the two pieces: the king on f1 and the rook on g1 trade places.
The bishops stand on b1 and e1; their long diagonals reach h7 and a5 once the c- and d-pawns step aside.
The second rank carries 2 pawns with no defender at all: b2, h2.
The setup belongs to the BastionScout family; read right to left it becomes position 253.
The engine's main line opens with c4.
Morozov Balance Index: 80 of 100 — class A — most balanced. Engine evaluation of the starting position: +17 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #616Provenance
Mined from the project's engine self-play games.
Pack 011 · SP-616
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads