Mate in 3: bishop to c6 (h1·2)
c9-20723naming 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 1860 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 e1, rook d4 c7 a8, bishop h1, pawn a2 b2 e3 h4.
Black: king b5, knight c4, pawn a4 b6 c6 d6.
9 white and 6 black pieces are on the board; the puzzle position arises after move 34.
The position in numbers
White are ahead by 15 points of material (22 against 7; 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 b5.
It is White to move on move 34, with 43 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 — natural highways for the rooks and queen. Half-open for White: c, d.
The White king has 4 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
34. Bxc6+ Kb4 35. Rxa4+ Kc5 36. Raxc4#
Why it works
- Best move. bishop to c6 is exactly what the engine plays (#2).
- Spot on — rook to a4 (#1).
- Precise: rook to c4 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Kb4, then Rxa4+ and you stay on top.
Move by move
- 34. Bxc6+ — bishop to c6 (capture) with check
- Kb4 — king to b4
- 35. Rxa4+ — rook to a4 (capture) with check
- Kc5 — king to c5
- 36. Raxc4# — rook to c4 (capture) and it is checkmate
Types in this puzzle
Ladder mate
Two heavy pieces climb line by line, cutting off every retreat.
The ladder mate uses two heavy pieces climbing rung by rung: one cuts the king off along a line, the other checks on the next line, driving him toward the edge. It is the classic two-rook technique — check, the king retreats one rank, the other rook checks, until mate on the last rank. The only danger is the king creeping close enough to attack one of your rooks. If it does, simply slide that rook to the far side of the same line.
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.
Absolute pin
A piece is pinned against its king — it cannot legally move.
An absolute pin freezes a piece on the line between its own king and your long-range attacker: moving it is simply illegal. The pattern is three units on one straight line — your bishop, rook or queen, an enemy piece, and the enemy king behind it. A pinned piece neither attacks nor defends anything: treat it as if it were off the board. Pile up on it, ideally with a pawn, because running away is against the rules.
About this position
These pieces come from starting position #439.
SP-439 · BastionGuard — The king starts one file off-centre, on c or f, with neither knight in a corner.
The king starts on f1, the rooks on a1 and g1, the queen on e1.
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 h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
The second rank carries 2 pawns with no defender at all: c2, h2.
The setup belongs to the BastionGuard family; read right to left it becomes position 706.
The engine's main line opens with g4.
Morozov Balance Index: 47 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +27 centipawns for White (depth 42, 400 000 000 nodes).
Explore position #439Provenance
Mined from the project's engine self-play games.
Pack 013 · SP-439
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