Winning blow: knight to b5 (a7·5)
c9-24453naming 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 1390 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 e1, rook c1 g1, bishop a1 h1, knight a7, pawn a2 f2 b3 g3 h3 c4.
Black: king e8, rook f6 c7, bishop a8 h8, knight f8, pawn d5 e5 b6 d7 h7.
12 white and 11 black pieces are on the board; the puzzle position arises after move 17.
The position in numbers
White are ahead by 1 points of material (25 against 24; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on e1, the black king on e8.
It is White to move on move 17, with 32 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 5. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: d, e.
The White king has 6 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
17. Nb5 Rc5 18. b4 Rc8 19. O-O Ng6 20. cxd5
Why it works
- Great move! knight to b5 keeps the pressure (+4.4).
- pawn to b4 develops smoothly.
- A natural move: king to g1.
- Best move. pawn to d5 is exactly what the engine plays (+4.3).
- You reach a winning position (+4.3).
- If instead Rc5, then b4 and you stay on top.
Move by move
- 17. Nb5 — knight to b5
- Rc5 — rook to c5
- 18. b4 — pawn to b4
- Rc8 — rook to c8
- 19. O-O — king to g1
- Ng6 — knight to g6
- 20. cxd5 — pawn to d5 (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.
Quiet move
No check, no capture — yet this modest move decides the game.
A quiet move gives no check and takes nothing — yet it decides the game by creating an unstoppable threat or stealing the king's last square. This is the hardest class of moves: the eye hunts for loud blows while a modest shift does the winning. The clue: every forcing try runs into a defense, so seek the move that strengthens the threat or takes squares away. Train yourself to ask: what if I neither capture nor check, but quietly improve?
About this position
These pieces come from starting position #227.
SP-227 · ThroneGuard — King home on d or e, knights kept off the a- and h-files — the family of the standard starting array.
The king starts on e1, the rooks on c1 and g1, the queen on d1.
Castling ends where it always does: king to g1 and rook to f1 on the short side, king to c1 and rook to d1 on the long one.
A bishop starts in the corner on a1: it has a single diagonal, which the b-pawn unlocks, running out to h8.
One second-rank pawn starts with no defender at all: a2.
The setup belongs to the ThroneGuard family; read right to left it becomes position 627.
The engine's main line opens with g3.
Morozov Balance Index: 47 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +27 centipawns for White (depth 47, 400 000 000 nodes).
Explore position #227Provenance
Mined from the project's engine self-play games.
Pack 010 · SP-227
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