Winning blow: knight to b8 (a6·2)
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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 1060 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 f1, rook d1 g1, bishop a1 c2, knight a6, pawn a2 b2 d2 e2 f2 h2 c4 g5.
Black: king g8, queen b8, rook d8 f8, bishop h1, knight c8 e8, pawn h5 b6 g6 a7 d7 e7 f7.
14 white and 14 black pieces are on the board; the puzzle position arises after move 10.
The position in numbers
Black are ahead by 8 points of material (27 against 35; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on f1, the black king on g8.
It is White to move on move 10, with 34 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.
White hold the bishop pair, an edge in open lines. 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
10. Nxb8 Bb7 11. Ba4 b5 12. Bxb5
Why it works
- Great move! knight to b8 keeps the pressure (+2.3).
- Well found: bishop to a4 (+2.8).
- Strong! bishop to b5 is the sharp choice (+2.5).
- You win a piece — the queen.
- If instead Bb7, then Ba4 and you win the queen.
Move by move
- 10. Nxb8 — knight to b8 (capture)
- Bb7 — bishop to b7
- 11. Ba4 — bishop to a4
- b5 — pawn to b5
- 12. Bxb5 — bishop to b5 (capture)
Types in this puzzle
First-rank tactic
Pieces still on their starting rank become targets of a first-rank strike.
The first-rank tactic: enemy pieces that never left their starting rank become targets themselves. Standing shoulder to shoulder, they block each other and are often defended by nobody. Look for a strike along the first or eighth rank — a rook or queen that breaks through harvests the undeveloped pieces. The mistake is treating the back rank as a safe "rear area": in Chess960 it can be the most vulnerable place on the board.
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.
Winning blow
Find the strike that wins material by force.
A winning blow is a forced material gain that does not fit a single textbook motif. The general tactical recipe applies: spot loose pieces, an awkwardly placed king, overloaded lines. Go through the forcing moves in order of violence — checks, captures, threats — because most combinations start with one of them. Do not judge by feel: calculate the concrete line until the outcome is beyond doubt.
About this position
These pieces come from starting position #176.
SP-176 · BastionGuard — A c- or f-file king and two knights on inner files (b–g).
The king starts on f1, the rooks on d1 and g1, the queen on h1.
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 pawn on f2 is defended by the king alone — the classic soft spot of the standard setup.
The setup belongs to the BastionGuard family; read right to left it becomes position 783.
The engine's main line opens with g4.
Morozov Balance Index: 2 of 100 — class D — largest edge. Engine evaluation of the starting position: +53 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #176Provenance
Mined from the project's engine self-play games.
Verified by Stockfish at depth 20+.
Solution forcedness confirmed (verified).
Pack 006 · SP-176
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