Winning blow: pawn to a6
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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 1200 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 c3, rook b1 e1, bishop d6, knight d1 c7, pawn c2 d2 e2 b4 h4 a5.
Black: king b7, queen e4, rook c8 e8, bishop h1 h8, knight f7 f8, pawn b6 f6 g6 a7 d7 h7.
13 white and 14 black pieces are on the board; the puzzle position arises after move 15.
The position in numbers
Black are ahead by 3 points of material (34 against 37; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on c1, the black king on b7.
It is White to move on move 15, with 45 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 6. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: f, g.
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
15. a6+ Kb8 16. Nxe8+ Nxd6 17. Nxd6 Rxc3 18. Nxe4
Why it works
- Great move! pawn to a6 keeps the pressure (+3.9).
- Well found: knight to e8 (+4.1).
- Strong! knight to d6 is the sharp choice (+4.1).
- Great move! knight to e4 keeps the pressure (+4.0).
- You win a piece — the queen.
- If instead Kb8, then Nxe8+ and you win the rook.
Move by move
- 15. a6+ — pawn to a6 with check
- Kb8 — king to b8
- 16. Nxe8+ — knight to e8 (capture) with check
- Nxd6 — knight to d6 (capture)
- 17. Nxd6 — knight to d6 (capture)
- Rxc3 — rook to c3 (capture)
- 18. Nxe4 — knight to e4 (capture)
Types in this puzzle
Knight fork
One knight move attacks two targets at once — the opponent can only save one.
A fork is one move that attacks two targets at once, and no piece forks better than the knight. Look through the knight's eyes: it jumps in an L and never moves along straight lines, which is exactly why its threats get missed. Both victims of a knight fork always stand on squares of one color, while the knight strikes from the opposite color. Hunt for the square from which the knight hits the king and a heavy piece at once.
Only move
Everything else loses — find the only move that holds.
An only move is a position where everything loses except one single continuation. You cannot play "by hand" here: run through fundamentally different defenses — run away, block, trade, counterattack — and discard the ones that fail. The hallmark of these puzzles is that the obvious moves lose quickly while the solution often looks strange. First understand exactly what the threat is — then the one saving move reveals itself.
Counter-strike
Don't defend — answer the threat with a bigger one.
The counter-strike: instead of defending against the threat, you answer with a bigger threat of your own. While your opponent grabs a pawn, you deliver mate — the arithmetic favors you. Look for a counter when direct defenses fail: do you have a check, an attack on the queen, a mating threat? The beginner's error is meeting every threat with a reflexive defense without checking the counterattacking resources first.
About this position
These pieces come from starting position #783.
SP-783 · BastionGuard — King shifted to c or f, knights kept clear of the edges — 168 positions in all.
The king starts on c1, the rooks on b1 and e1, the queen on a1.
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.
The pawn on c2 is defended by the king alone — the same soft spot f2 is in the classical setup.
The setup belongs to the BastionGuard family; read right to left it becomes position 176.
The engine's main line opens with b4.
Morozov Balance Index: 6 of 100 — class D — largest edge. Engine evaluation of the starting position: +48 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #783Provenance
Mined from the project's engine self-play games.
Pack 008 · SP-783
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