Attack on the uncastled king: rook to b7 (b3·6)
c9-24641naming 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.
An opening trap from this Chess960 starting position.
A piece strikes across the board from its Chess960 starting square.
Mate in 2: the first move creates an unstoppable threat, the second delivers mate.
Uncastled king: the enemy king is stuck in the centre — punish it before it castles.
Difficulty 1450 ShuffleRating — club-player level.
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.
Early Chess960 traps punish natural but careless development. Look for a forcing move that exploits a piece the opponent has just placed on a poor square — a fork, a pin or a threat that wins material before either side is fully developed.
From some Chess960 setups a bishop or queen rakes a long diagonal straight from move one. Trace those long-range lines into the enemy camp: a single opened file or diagonal can create an immediate pin, skewer or mating threat.
Mate in two usually opens with a forcing move — a check, a capture or an unstoppable threat — that strips the king of squares or defenders, so the follow-up mate becomes unavoidable. Look for the first move that leaves the opponent only losing replies.
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.
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 f1, rook c1 b3, bishop d1 e1, knight g1 h1, pawn b2 c2 d2 g2 h2 e3 a4.
Black: king b8, queen f8, rook a8 c8, bishop d6 e8, knight g6 g8, pawn f4 a7 b7 c7 d7 f7 g7 h7.
15 white and 16 black pieces are on the board; the puzzle position arises after move 6.
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 b1, the black king on b8.
It is White to move on move 6, with 40 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: f.
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
6. Rxb7+ Kxb7 7. Qb5#
Why it works
- Great move! rook to b7 keeps the pressure (#1).
- Well found: queen to b5 (#).
- The line ends in a forced mate in 2.
- If instead Kxb7, then Qb5# and it is mate.
Move by move
- 6. Rxb7+ — rook to b7 (capture) with check
- Kxb7 — king to b7 (capture)
- 7. Qb5# — queen to b5 and it is checkmate
Types in this puzzle
Epaulette mate
The king's own pieces flank it like epaulettes — mate comes head-on.
In the epaulette mate the king stands between two of its own pieces — most often rooks — like an officer wearing epaulettes. The side squares are blocked by friends, there is no retreat, and the queen mates head-on from directly in front of the king. The sign: a king on the edge rank with both neighboring squares on that rank occupied by its own pieces. Remember, extra defenders crowding the king can be deadlier than no defenders at all.
Long-range opener
From its unusual home square a long-range piece strikes across the board.
The long-range opener: a bishop, rook or queen strikes across the whole board straight from its starting area. In Chess960 the long-range pieces sit on unfamiliar squares, and a single pawn move can uncover a shot deep into the enemy camp. In the opening, trace with your eyes the diagonals and files of every long-range piece — yours and theirs. The mistake is pushing a pawn without checking whose line you have just opened.
Mate in 2
A forced checkmate in two moves.
Mate in two: your move, any reply, then the mating blow. Start with the most forcing first moves — checks and sacrifices that shrink the opponent's options to almost nothing. Against every single reply you must have a mate ready, so check them all without exception. The common failure is analyzing the pretty defense and forgetting the boring one.
About this position
These pieces come from starting position #921.
SP-921 · RampartScout — Wing king plus a rim knight, and only 72 positions qualify — the rarest pattern of all.
The king starts on b1, the rooks on a1 and c1, the queen on f1.
From b1 the king makes the longest journey Chess960 allows when castling short: five squares to g1.
The bishops stand on d1 and e1; their long diagonals reach h5 and a5 once the e- and d-pawns step aside.
One second-rank pawn starts with no defender at all: h2.
The setup belongs to the RampartScout family; read right to left it becomes position 41.
The engine's main line opens with a4.
Morozov Balance Index: 89 of 100 — class A — most balanced. Engine evaluation of the starting position: +14 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #921Provenance
Mined from the project's engine self-play games.
Pack 011 · SP-921
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