Attack on the uncastled king: king to a2 (b1·5)
c9-17711naming 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 970 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 b1, queen g2, rook a1 g4, bishop c1, knight h2, pawn c2 f2 c3 d3 e3 a4.
Black: king b8, queen b6, rook a8 g8, bishop c8, pawn d4 a5 g5 b7 c7 f7.
12 white and 11 black pieces are on the board; the puzzle position arises after move 18.
The position in numbers
White are ahead by 3 points of material (31 against 28; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on b1, the black king on b8.
It is White to move on move 18, with 2 legal replies to weigh — only the line that keeps the advantage solves the puzzle. White are in check right now, so every reply must answer the check.
White keeps 6 pawns, Black 6. Files fully open (no pawns of either colour): h — natural highways for the rooks and queen. Half-open for White: b, g.
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
18. Ka2 Be6+ 19. c4 Qb4 20. Rxd4
Why it works
- Great move! king to a2 keeps the pressure (+2.6).
- Well found: pawn to c4 (+3.5).
- Precise: rook to d4 is the top choice (+2.5).
- You reach a winning position (+2.5).
- If instead dxe3, then fxe3 and you stay on top.
Move by move
- 18. Ka2 — king to a2
Types in this puzzle
Winning blow
Find the strike that wins material by force.
A winning blow is a forced material gain that does not fit a single textbook motif. The general tactical recipe applies: spot loose pieces, an awkwardly placed king, overloaded lines. Go through the forcing moves in order of violence — checks, captures, threats — because most combinations start with one of them. Do not judge by feel: calculate the concrete line until the outcome is beyond doubt.
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 #743.
SP-743 · RampartGuard — A wing king (b/g) with no knight on the a- or h-file.
The king starts on b1, the rooks on a1 and g1, the queen on f1.
From b1 the king makes the longest journey Chess960 allows when castling short: five squares 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: h2.
The setup belongs to the RampartGuard family; read right to left it becomes position 402.
The engine's main line opens with a4.
Morozov Balance Index: 69 of 100 — class B — balanced. Engine evaluation of the starting position: +21 centipawns for White (depth 47, 400 000 000 nodes).
Explore position #743Provenance
Mined from the project's engine self-play games.
Pack 005 · SP-743
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