Mate in 3: queen to b6 (c5·4)
c9-08949naming 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 1980 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 d1, queen c5, rook a7, bishop g2 h4, knight a1 g5, pawn a2 b2 d2 e2.
Black: king c8, rook d8 g8, bishop f3, knight b6, pawn c6 b7 d7 e7.
11 white and 9 black pieces are on the board; the puzzle position arises after move 18.
The position in numbers
White are ahead by 10 points of material (30 against 20; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on d1, the black king on c8.
It is White to move on move 18, with 50 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): f, g, h — natural highways for the rooks and queen. Half-open for White: c.
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
18. Qxb6 Bxe2+ 19. Kxe2 Rde8 20. Ra8#
Why it works
- Great move! queen to b6 keeps the pressure (#2).
- Spot on — king to e2 (#1).
- Precise: rook to a8 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Bxe2+, then Kxe2 and you win the bishop.
Move by move
- 18. Qxb6 — queen to b6 (capture)
- Bxe2+ — bishop to e2 (capture) with check
- 19. Kxe2 — king to e2 (capture)
- Rde8 — rook to e8
- 20. Ra8# — rook 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.
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 #315.
SP-315 · ThroneScout — Centre-file king, rim knight: 204 of the 960 positions share this pattern.
The king starts on d1, the rooks on c1 and f1, the queen on b1.
Castling long simply swaps the two pieces: the king on d1 and the rook on c1 trade places.
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: h2.
The setup belongs to the ThroneScout family; read right to left it becomes position 353.
The engine's main line opens with c4.
Morozov Balance Index: 40 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +29 centipawns for White (depth 48, 400 000 000 nodes).
Explore position #315Provenance
Mined from the project's engine self-play games.
Pack 014 · SP-315
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