Winning blow: knight to c5 (b3·10)
c9-24644naming 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 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 b1, queen e1, rook a1 c2, bishop c4, knight b3, pawn g3 a4 f4 e5.
Black: king c8, queen c6, rook a7 c7, bishop c5 e8, knight b8, pawn b4 g4 f5 e6.
10 white and 11 black pieces are on the board; the puzzle position arises after move 37.
The position in numbers
Black are ahead by 3 points of material (29 against 32; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on b1, the black king on c8.
It is White to move on move 37, with 39 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 4 pawns, Black 4. Files fully open (no pawns of either colour): c, d, h — natural highways for the rooks and queen. Half-open for White: b.
Black 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
37. Nxc5 Bd7 38. Bb3 Na6 39. Nxe6 Qxc2+ 40. Bxc2
Why it works
- Brilliant! The knight on c5 is a sacrifice that works — you stand better (+1.3).
- bishop to b3 develops smoothly.
- Precise: knight to e6 is the top choice (+1.5).
- Best move. bishop to c2 is exactly what the engine plays (+1.8).
- You win a piece — the queen.
- If instead Bd7, then Bb3 and you win the bishop.
Move by move
- 37. Nxc5 — knight to c5 (capture)
- Bd7 — bishop to d7
- 38. Bb3 — bishop to b3
- Na6 — knight to a6
- 39. Nxe6 — knight to e6 (capture)
- Qxc2+ — queen to c2 (capture) with check
- 40. Bxc2 — bishop to c2 (capture)
Types in this puzzle
Discovered attack
A piece steps aside and opens a second attack from the piece behind it.
A discovered attack works like a curtain: one piece steps off the line and unveils the long-range piece behind it. The beauty is that the moving piece can create a second threat of its own — two attacks in one move. Look for your stacked pairs: a bishop or rook behind a knight or pawn, aimed through them at something valuable. Send the front piece to the most aggressive square — a discovery without a second threat wastes half its power.
Overload
One defender guards two things — it cannot do both jobs.
Overloading exploits a defender with two jobs at once — guarding a piece and covering a mating square, for instance. It cannot do both: your first strike forces it to handle one duty and abandon the other. Find the overworked piece by asking what happens to each of its charges if it gets distracted. Then hit one target and collect the other — an overloaded defender only pretends to defend.
About this position
These pieces come from starting position #650.
SP-650 · BastionScout — The king starts one file off-centre, on c or f, and a knight begins in a corner.
The king starts on c1, the rooks on a1 and d1, the queen on g1.
The king already stands on c1, so castling long moves only the rook, from a1 to d1.
The bishops stand on e1 and f1; their long diagonals reach a5 and a6 once the d- and e-pawns step aside.
The pawn on b2, c2 is defended by the king alone — the same soft spot f2 is in the classical setup.
The setup belongs to the BastionScout family; read right to left it becomes position 213.
The engine's main line opens with d4, putting a pawn straight into the centre.
Morozov Balance Index: 43 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +28 centipawns for White (depth 47, 400 000 000 nodes).
Explore position #650Provenance
Mined from the project's engine self-play games.
Pack 008 · SP-650
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