Winning blow: queen to a8 (a5·3)
c9-13919naming 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.
Winning tactic: there is a move that gains a decisive advantage — find it.
Difficulty 1150 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.
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 c1, queen a5, rook d1 a3, knight d2, pawn b2 c2 h2 d3 g3 a4 d4.
Black: king b8, queen f3, rook d8, bishop f6 f7, knight a8, pawn c4 d5 f5 b6 g6 h7.
12 white and 12 black pieces are on the board; the puzzle position arises after move 21.
The position in numbers
Material is level — 29 points of pieces on each side (pawn = 1, knight and bishop = 3, rook = 5, queen = 9).
The white king stands on c1, the black king on b8.
It is White to move on move 21, with 31 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 7 pawns, Black 6. Files fully open (no pawns of either colour): e — natural highways for the rooks and queen. Half-open for White: f.
Black hold the bishop pair, an edge in open lines. 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
21. Qxa8+ Kxa8 22. Nxf3
Why it works
- Great move! queen to a8 keeps the pressure (+3.8).
- Well found: knight to f3 (+3.9).
- You win a piece — the queen.
- If instead Kxa8, then Nxf3 and you win the queen.
Move by move
- 21. Qxa8+ — queen to a8 (capture) with check
- Kxa8 — king to a8 (capture)
- 22. Nxf3 — knight to f3 (capture)
Types in this puzzle
Relative pin
A piece shields a more valuable one behind it — moving it loses material.
In a relative pin the piece shields not its king but something valuable behind it, usually the queen. Moving is legal but costly, because the piece behind falls. Look for three units on one line: your long-range piece, a cheaper enemy piece, and an expensive one hiding behind. Beware the classic trap — a relatively pinned piece can still move with check or a bigger threat, so verify before you cash in.
Simplification
Trade the heavy pieces and steer into a won endgame.
Simplification is how you convert an advantage: by trading queens and rooks you extinguish the counterplay and steer the game into a won endgame. The rule is simple — the side with extra material trades pieces but keeps pawns. Look for exchanges once the material is already won and your opponent is still rattling threats. The mistake is avoiding the queen trade and letting him muddy the water forever.
About this position
These pieces come from starting position #367.
SP-367 · BastionScout — A c- or f-file king with at least one knight out on the edge.
The king starts on c1, the rooks on b1 and d1, the queen on e1.
The king already stands on c1, so castling long moves only the rook, from b1 to d1.
A bishop starts in the corner on h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
One second-rank pawn starts with no defender at all: a2.
The setup belongs to the BastionScout family; read right to left it becomes position 304.
The engine's main line opens with f4.
Morozov Balance Index: 65 of 100 — class B — balanced. Engine evaluation of the starting position: +22 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #367Provenance
Mined from the project's engine self-play games.
Pack 007 · SP-367
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