Attack on the uncastled king: knight to b7 (a5·24)
c9-17931naming 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 c1, rook d1 h1, bishop g1 b5, knight b1 a5, pawn a2 b2 d2 g2 h2 f3 e4.
Black: king e8, queen c8, rook d8 h8, bishop f8 g8, knight c6 a8, pawn d4 e5 f6 a7 b7 g7 h7.
15 white and 15 black pieces are on the board; the puzzle position arises after move 8.
The position in numbers
Material is level — 38 points of pieces on each side (pawn = 1, knight and bishop = 3, rook = 5, queen = 9).
The white king stands on e1, the black king on e8.
It is White to move on move 8, with 34 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 7 pawns, Black 7. Files fully open (no pawns of either colour): c — natural highways for the rooks and queen.
The White king has 3 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
8. Nxb7 Bb4 9. Bxc6+
Why it works
- Great move! knight to b7 keeps the pressure (+4.7).
- Spot on — bishop to c6 (+4.3).
- You win a piece — the knight.
- If instead Bb4, then Bxc6+ and you win the knight.
Move by move
- 8. Nxb7 — knight to b7 (capture)
- Bb4 — bishop to b4
- 9. Bxc6+ — bishop to c6 (capture) with check
Types in this puzzle
King in the center
The king starts in the middle — and the storm reaches it first.
King in the center: in Chess960 the monarch may start on the d- or e-file, right in the line of fire, and the attack can reach him before he ever castles. The signs: the enemy king still sits on its central starting square while the files toward it are opening. Play to rip the center open — a pawn sacrifice usually pays off here. And if it is your king in the middle, castle at the very first opportunity.
Win the pinned piece
The pinned piece cannot run — attack it again and win it.
A pinned piece cannot flee, which means you can win it outright by attacking it one more time. Count attackers against defenders: if you outnumber them, the piece is yours. The best extra attacker is a pawn, since it costs less than anything it might capture. Do not rush the capture — build up the pressure first, then harvest.
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 #46.
SP-46 · ThroneScout — A knight starts on the edge (a/h) and the king sits centrally on d or e; the mirror twin stays in this family too.
The king starts on e1, the rooks on d1 and h1, the queen on c1.
The queenside rook already stands on d1, so castling long moves only the king, from e1 to c1.
The bishops stand on f1 and g1; their long diagonals reach a6 and a7 once the e- and f-pawns step aside.
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 916.
The engine's main line opens with e4, putting a pawn straight into the centre.
Morozov Balance Index: 75 of 100 — class A — most balanced. Engine evaluation of the starting position: +19 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #46Provenance
Mined from the project's engine self-play games.
Pack 004 · SP-46
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