Attack on the uncastled king: pawn to b6 (b5)
c9-11364naming 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 920 ShuffleRating — for beginners taking their first steps in Chess960 tactics.
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 e1, queen d1, rook a1 h1, bishop e3 a4, knight f1 h3, pawn a2 b2 e2 f2 g2 h2 d4 b5.
Black: king e8, queen e7, rook a8 f8, bishop a7 c8, knight d5 f7, pawn f5 a6 d6 e6 g6 c7 h7.
16 white and 15 black pieces are on the board; the puzzle position arises after move 12.
The position in numbers
White are ahead by 1 points of material (39 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 12, with 31 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 8 pawns, Black 7. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: c.
The White king has 1 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
12. b6+ Bd7 13. bxa7
Why it works
- Great move! pawn to b6 keeps the pressure (+4.3).
- Spot on — pawn to a7 (+4.2).
- You win a piece — the bishop.
- If instead Bd7, then bxa7 and you win the bishop.
Move by move
- 12. b6+ — pawn to b6 with check
- Bd7 — bishop to d7
- 13. bxa7 — pawn to a7 (capture)
Types in this puzzle
Discovered check
The moving piece opens a check — and is free to grab anything meanwhile.
With a discovered check the moving piece unmasks a check from the piece standing behind it. While the king deals with the check, the piece that moved grabs whatever it likes, free of charge. Look for your long-range piece on a line with the enemy king, with exactly one of your own pieces in between. The rule: among all the ways to step aside, pick the one that captures or attacks the most expensive loot.
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 #884.
SP-884 · 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 a1 and f1, the queen on d1.
The kingside rook already stands on f1, so castling short moves only the king, from e1 to g1.
The bishops stand on b1 and c1; their long diagonals reach h7 and h6 once the c- and d-pawns step aside.
The second rank carries 2 pawns with no defender at all: g2, h2.
The setup belongs to the ThroneScout family; read right to left it becomes position 78.
The engine's main line opens with c3.
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 #884Provenance
Mined from the project's engine self-play games.
Pack 004 · SP-884
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