Mate in 3: bishop to b1
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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 b3, queen a5, rook f8, bishop c2, pawn d3 h3 c4 c5.
Black: king d7, queen b1, pawn e5 h5 c6 a7 b7.
8 white and 7 black pieces are on the board; the puzzle position arises after move 39.
The position in numbers
White are ahead by 7 points of material (21 against 14; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on b3, the black king on d7.
It is White to move on move 39, with 4 legal replies to weigh — only the line that keeps the advantage solves the puzzle. White are in check right now, so every reply must answer the check.
White keeps 4 pawns, Black 5. Files fully open (no pawns of either colour): f, g — natural highways for the rooks and queen. Half-open for White: a, b, e.
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
39. Bxb1 e4 40. Qd8+ Ke6 41. Qd6#
Why it works
- Great move! bishop to b1 keeps the pressure (#2).
- Spot on — queen to d8 (#1).
- Precise: queen to d6 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead e4, then Qd8+ and you win the queen.
Move by move
- 39. Bxb1 — bishop to b1 (capture)
- e4 — pawn to e4
- 40. Qd8+ — queen to d8 with check
- Ke6 — king to e6
- 41. Qd6# — queen to d6 and it is checkmate
Types in this puzzle
Supported queen mate
The queen delivers mate face to face, protected by a friend.
The supported queen mate is the most common pattern of all: the queen lands next to the king and mates because a friendly piece or pawn protects her. The king is helpless — capturing is impossible, and the queen covers every neighboring square herself. Hunt for a protected square beside the enemy king: a knight, bishop or pawn eyeing it turns her invasion into mate. Verify one thing — that the square really is defended, or the king eats her.
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 #348.
SP-348 · ThroneScout — King on a central file (d/e) with a knight starting on the rim (a/h).
The king starts on d1, the rooks on c1 and f1, the queen on e1.
Castling long simply swaps the two pieces: the king on d1 and the rook on c1 trade places.
The bishops stand on b1 and g1; their long diagonals reach h7 and a7 once the c- and f-pawns step aside.
The second rank carries 2 pawns with no defender at all: b2, g2.
The setup belongs to the ThroneScout family; read right to left it becomes position 332.
The engine's main line opens with f4.
Morozov Balance Index: 1 of 100 — class D — largest edge. Engine evaluation of the starting position: +62 centipawns for White (depth 43, 400 000 000 nodes).
In 50 self-play games White scored 56.0% (95% CI 42.3–68.8%).
Explore position #348Provenance
Mined from the project's engine self-play games.
Pack 012 · SP-348
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