Attack on the uncastled king: pawn to e5 (f4·98)
c9-23178naming 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 1700 ShuffleRating — for advanced tacticians.
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 f1, rook a1 g1, bishop c1 h1, knight e3 c4, pawn a2 b2 h2 c3 d3 g3 f4.
Black: king e8, queen e6, rook a8 g8, bishop c8 h8, knight f6 d8, pawn a5 e5 f5 g6 b7 c7 e7 h7.
15 white and 16 black pieces are on the board; the puzzle position arises after move 10.
The position in numbers
Black are ahead by 1 points of material (38 against 39; 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 10, with 39 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 7 pawns, Black 8. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: e.
The White king has 4 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
10. fxe5 Ng4 11. Bd5 Nxe3 12. Nxe3 Qxe5 13. Bxg8
Why it works
- Great move! pawn to e5 keeps the pressure (+3.6).
- Well found: bishop to d5 (+3.9).
- Precise: knight to e3 is the top choice (+4.1).
- Great move! bishop to g8 keeps the pressure (+4.1).
- You win a piece — the rook.
- If instead Ng4, then Bd5 and you stay on top.
Move by move
- 10. fxe5 — pawn to e5 (capture)
- Ng4 — knight to g4
- 11. Bd5 — bishop to d5
- Nxe3 — knight to e3 (capture)
- 12. Nxe3 — knight to e3 (capture)
- Qxe5 — queen to e5 (capture)
- 13. Bxg8 — bishop to g8 (capture)
Types in this puzzle
First-rank tactic
Pieces still on their starting rank become targets of a first-rank strike.
The first-rank tactic: enemy pieces that never left their starting rank become targets themselves. Standing shoulder to shoulder, they block each other and are often defended by nobody. Look for a strike along the first or eighth rank — a rook or queen that breaks through harvests the undeveloped pieces. The mistake is treating the back rank as a safe "rear area": in Chess960 it can be the most vulnerable place on the board.
Deflection
Force the defender away from its duty — then strike what it guarded.
Deflection forces the guard to leave its post: a sacrifice or exchange drags it away from the piece or square it protects. First find the critical defender — the piece whose absence makes the mate or the material win possible. Then find the move it cannot ignore, which is usually a capture. Do not be stingy: if removing the guard wins the queen or mates, the sacrifice pays for itself many times over.
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 #455.
SP-455 · ThroneGuard — King home on d or e, knights kept off the a- and h-files — the family of the standard starting array.
The king starts on e1, the rooks on a1 and g1, the queen on f1.
Castling ends where it always does: king to g1 and rook to f1 on the short side, king to c1 and rook to d1 on the long one.
A bishop starts in the corner on h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
The second rank carries 2 pawns with no defender at all: c2, h2.
The setup belongs to the ThroneGuard family; read right to left it becomes position 690.
The engine's main line opens with f4.
Morozov Balance Index: 91 of 100 — class A — most balanced. Engine evaluation of the starting position: +13 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #455Provenance
Mined from the project's engine self-play games.
Pack 013 · SP-455
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