Mate in 2: queen to b7 (a8)
c9-01944naming 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.
Mate in 2: the first move creates an unstoppable threat, the second delivers mate.
A fork made possible by the Chess960 piece placement.
Difficulty 1320 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.
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.
A set-up fork needs one preparing move before the fork lands — a check that drives the king onto the forking square, or a capture that lines the targets up. Find the preparation first, then the fork it makes possible.
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 d1, queen a8, rook a1 f1, bishop b1 e1, knight g1 c5, pawn a2 b2 c2 d2 e2 h2 f3 g3.
Black: king c8, queen h8, rook f8, bishop b8 e8, knight c4 e4, pawn g6 a7 c7 d7 e7 f7 h7.
16 white and 14 black pieces are on the board; the puzzle position arises after move 7.
The position in numbers
White are ahead by 6 points of material (39 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 d1, the black king on c8.
It is White to move on move 7, with 31 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 8 pawns, Black 7. No file is fully open, so the heavy pieces have to be pried in.
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
7. Qb7+ Kd8 8. Qxb8#
Why it works
- Great move! queen to b7 keeps the pressure (#1).
- Well found: queen to b8 (#).
- The line ends in a forced mate in 2.
- If instead Kd8, then Qxb8# and it is mate.
Move by move
- 7. Qb7+ — queen to b7 with check
- Kd8 — king to d8
- 8. Qxb8# — queen to b8 (capture) and it is checkmate
Types in this puzzle
Back-rank mate
The king is locked behind its own pawns — a heavy piece strikes the last rank.
The back-rank mate strikes a king locked behind its own unmoved pawns when a rook or queen crashes onto the last rank. The signs: no escape hole in front of the king, and the back rank guarded by a single piece or by nobody at all. Often that lone guard is deflected or traded off first, and only then comes the invasion. In your own games, make luft in time — one pawn move prevents a sudden catastrophe.
Setup fork
The random setup allows a fork that classical chess never sees.
A setup fork is a double attack that exists only because of the unusual starting squares — in classical chess these targets never stand side by side. Look for pairs of undefended pieces on your opponent's back rank and for squares from which a knight or pawn hits both at once. Such forks usually appear within the first moves, before the pieces disperse. In every new position, note right away which starting pieces are defended by no one.
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 #664.
SP-664 · ThroneGuard — A centre-file king with no knight on the edge; a position and its mirror twin always share this family.
The king starts on d1, the rooks on a1 and f1, the queen on h1.
The kingside rook already stands on f1, so castling short moves only the king, from d1 to g1.
The bishops stand on b1 and e1; their long diagonals reach h7 and a5 once the c- and d-pawns step aside.
One second-rank pawn starts with no defender at all: b2.
The setup belongs to the ThroneGuard family; read right to left it becomes position 205.
The engine's main line opens with c3.
Morozov Balance Index: 75 of 100 — class B — balanced. Engine evaluation of the starting position: +19 centipawns for White (depth 47, 400 000 000 nodes).
Explore position #664Provenance
Mined from the project's engine self-play games.
Verified by Stockfish at depth 20+.
Solution forcedness confirmed (verified).
Pack 009 · SP-664
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads