Mate in 2: queen to d6 (a3·6)
c9-28419naming 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.
Mate in 2: the first move creates an unstoppable threat, the second delivers mate.
A fork made possible by the Chess960 piece placement.
Difficulty 1670 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.
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 g1, queen a3, rook e1, bishop h1 f4, knight b5, pawn b2 f2 h2 g3 a4.
Black: king d7, queen a7, rook h8, bishop c3 b7, knight e6 d8, pawn a5 b6 g6 f7 h7.
11 white and 12 black pieces are on the board; the puzzle position arises after move 24.
The position in numbers
Black are ahead by 3 points of material (28 against 31; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on g1, the black king on d7.
It is White to move on move 24, with 47 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 5 pawns, Black 5. Files fully open (no pawns of either colour): c, d, e — natural highways for the rooks and queen.
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
24. Qd6+ Ke8 25. Nc7#
Why it works
- Great move! queen to d6 keeps the pressure (#1).
- Well found: knight to c7 (#).
- The line ends in a forced mate in 2.
- If instead Ke8, then Nc7# and it is mate.
Move by move
- 24. Qd6+ — queen to d6 with check
- Ke8 — king to e8
- 25. Nc7# — knight to c7 and it is checkmate
Types in this puzzle
Knight mate
The knight lands the killing blow from its unique angle.
In a knight mate the final blow comes from the knight — the only piece whose check can never be blocked. That makes it lethal against a cramped king: only a king move or capturing the knight itself can help. The sign: the squares around the king are occupied or covered, and there is a hop from which the knight checks while staying untouchable. Bring the knight over early — it is slower than the long-range pieces, but its strike cannot be parried.
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 #503.
SP-503 · 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 b1.
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 pawn on e2 is defended by the king alone — the same soft spot f2 is in the classical setup.
The setup belongs to the ThroneGuard family; read right to left it becomes position 546.
The engine's main line opens with c3.
Morozov Balance Index: 24 of 100 — class D — largest edge. Engine evaluation of the starting position: +35 centipawns for White (depth 46, 400 000 000 nodes).
Explore position #503Provenance
Mined from the project's engine self-play games.
Pack 013 · SP-503
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