Attack on the uncastled king: rook to e5 (e1·2)
c9-10148naming 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 f1, queen g2, rook e1 g1, bishop a1 b1, pawn a2 d2 h2 b3 c4 f5.
Black: king f8, queen f7, rook d7 h8, bishop e5, knight c8 e8, pawn d4 c5 a7 g7 h7.
12 white and 12 black pieces are on the board; the puzzle position arises after move 15.
The position in numbers
Black are ahead by 2 points of material (31 against 33; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on f1, the black king on f8.
It is White to move on move 15, with 37 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): e — natural highways for the rooks and queen. Half-open for White: g.
White hold the bishop pair, an edge in open lines. 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
15. Rxe5 Re7 16. Rxc5
Why it works
- Great move! rook to e5 keeps the pressure (+3.1).
- Spot on — rook to c5 (+2.8).
- You win a piece — the bishop.
- If instead Re7, then Rxc5 and you win the bishop.
Move by move
- 15. Rxe5 — rook to e5 (capture)
- Re7 — rook to e7
- 16. Rxc5 — rook to c5 (capture)
Types in this puzzle
X-ray
A long-range piece acts through an enemy piece on the same line.
An X-ray lets a long-range piece act through an enemy piece standing on the same line — its power shines straight through. The square behind looks safe or defended, and that illusion is exactly what the tactic exploits. Check your rooks, bishops and queens: is a key square or a target hiding behind an enemy piece on their line? When counting captures on a square, include the X-ray attackers — they join the fight the moment the line opens.
Only move
Everything else loses — find the only move that holds.
An only move is a position where everything loses except one single continuation. You cannot play "by hand" here: run through fundamentally different defenses — run away, block, trade, counterattack — and discard the ones that fail. The hallmark of these puzzles is that the obvious moves lose quickly while the solution often looks strange. First understand exactly what the threat is — then the one saving move reveals itself.
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 #160.
SP-160 · BastionGuard — Both knights begin inside the board while the king stands on c or f; a position and its mirror twin share this family.
The king starts on f1, the rooks on d1 and h1, the queen on g1.
The queenside rook already stands on d1, so castling long moves only the king, from f1 to c1.
A bishop starts in the corner on a1: it has a single diagonal, which the b-pawn unlocks, running out to h8.
Every pawn on the second rank is defended from the very first move.
The setup belongs to the BastionGuard family; read right to left it becomes position 799.
The engine's main line opens with f3.
Morozov Balance Index: 9 of 100 — class D — largest edge. Engine evaluation of the starting position: +44 centipawns for White (depth 47, 400 000 000 nodes).
Explore position #160Provenance
Mined from the project's engine self-play games.
Pack 004 · SP-160
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