Mate in 3: knight to c5 (a4)
c9-21077naming 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.
Mate in 3: a forced sequence that ends in checkmate.
Difficulty 1630 ShuffleRating — for advanced tacticians.
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.
In a mate in three every move must be forcing; the defender should never get a free tempo. Find the check or threat that herds the king, calculate the single defence to each, and confirm the net closes on the third move.
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 a7, rook e1, knight a4, pawn a2 b2 c2 e2 h2.
Black: king c8, queen e8, rook d8, bishop g8, pawn a5 c5 e5 c6 g6 c7 h7.
9 white and 11 black pieces are on the board; the puzzle position arises after move 18.
The position in numbers
Black are ahead by 2 points of material (22 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 c1, the black king on c8.
It is White to move on move 18, with 25 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 5 pawns, Black 7. Files fully open (no pawns of either colour): d, f — natural highways for the rooks and queen. Half-open for White: g.
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
18. Nxc5 Rd1+ 19. Rxd1 Qd7 20. Qa8#
Why it works
- Great move! knight to c5 keeps the pressure (#2).
- Well found: rook to d1 (#1).
- Precise: queen to a8 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Rd1+, then Rxd1 and you win the rook.
Move by move
- 18. Nxc5 — knight to c5 (capture)
- Rd1+ — rook to d1 with check
- 19. Rxd1 — rook to d1 (capture)
- Qd7 — queen to d7
- 20. Qa8# — queen to a8 and it is checkmate
Types in this puzzle
Mate in 3
A forced checkmate in three moves.
Mate in three is a forced staircase: each of your moves narrows the opponent's choices, and the third one ends the game. Look for the start among checks and sacrifices — quiet first moves are rare in mating problems, but deliciously sneaky. Keep the tree in your head: every defense gets its own branch. Do not stop calculating after move two — see the final mating picture with your own eyes.
About this position
These pieces come from starting position #271.
SP-271 · 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 f1, 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 592.
The engine's main line opens with f4.
Morozov Balance Index: 10 of 100 — class D — largest edge. Engine evaluation of the starting position: +43 centipawns for White (depth 47, 400 000 000 nodes).
Explore position #271Provenance
Mined from the project's engine self-play games.
Pack 012 · SP-271
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