Mate in 2: queen to c8 (c1)
c9-24647naming 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.
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.
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.
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 c1, rook b1 e1, bishop d7, knight h5, pawn a2 f2 h2 g3 b4 d4.
Black: king f8, rook g6, bishop d6, knight e7, pawn b5 a6 f7 h7.
12 white and 8 black pieces are on the board; the puzzle position arises after move 25.
The position in numbers
White are ahead by 16 points of material (31 against 15; 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 f8.
It is White to move on move 25, with 48 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 4. Files fully open (no pawns of either colour): c, e — natural highways for the rooks and queen.
The White king has 3 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
25. Qc8+ Nxc8 26. Re8#
Why it works
- Best move. queen to c8 is exactly what the engine plays (#1).
- Well found: rook to e8 (#).
- The line ends in a forced mate in 2.
- If instead Nxc8, then Re8# and it is mate.
Move by move
- 25. Qc8+ — queen to c8 with check
- Nxc8 — knight to c8 (capture)
- 26. Re8# — rook to e8 and it is checkmate
Types in this puzzle
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.
Royal fork
A fork with check: the king must move, and the second piece is lost.
A royal fork is a fork with check — one of the two targets is the king itself. The check must be answered first, so nobody is left to rescue the second piece. Look for squares where your piece gives check and simultaneously attacks an undefended queen or rook. It is the most reliable fork of all, because your opponent literally has no choice.
Sacrifice attack
Give up material to unleash a decisive attack.
A sacrificial attack gives up material on purpose to rip the king's shelter open and launch a decisive assault. The sac is sound when you get concrete assets in return: open lines to the king, tempi, pieces ready to pour in. The signs: a poorly sheltered king, your forces aimed at its home, defenders stranded far away. The iron rule is to calculate, not hope — once the material is gone, there is no way back.
About this position
These pieces come from starting position #435.
SP-435 · BastionGuard — King shifted to c or f, knights kept clear of the edges — 168 positions in all.
The king starts on f1, the rooks on b1 and g1, the queen on e1.
Castling short simply swaps the two pieces: the king on f1 and the rook on g1 trade places.
A bishop starts in the corner on a1: it has a single diagonal, which the b-pawn unlocks, running out to h8.
The second rank carries 2 pawns with no defender at all: c2, h2.
The setup belongs to the BastionGuard family; read right to left it becomes position 707.
The engine's main line opens with b3.
Morozov Balance Index: 51 of 100 — class B — balanced. Engine evaluation of the starting position: +26 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #435Provenance
Mined from the project's engine self-play games.
Pack 011 · SP-435
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