Mate in 3: queen to c6 (b5·2)
c9-15083naming 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 2170 ShuffleRating — expert level — few solve it at first try.
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 h1, queen b5, rook f1 d7, knight e2, pawn a2 g2 g5.
Black: king b8, queen b2, rook f8, bishop f4, pawn f5 b6 a7 e7 h7.
8 white and 9 black pieces are on the board; the puzzle position arises after move 29.
The position in numbers
White are ahead by 3 points of material (25 against 22; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on h1, the black king on b8.
It is White to move on move 29, with 46 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 3 pawns, Black 5. Files fully open (no pawns of either colour): c, d — natural highways for the rooks and queen. Half-open for White: b, e, f, h.
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
29. Qc6 Bc7 30. Qxc7+ Ka8 31. Qxa7#
Why it works
- Great move! queen to c6 keeps the pressure (#2).
- Spot on — queen to c7 (#1).
- Precise: queen to a7 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Bc7, then Qxc7+ and you win the bishop.
Move by move
- 29. Qc6 — queen to c6
- Bc7 — bishop to c7
- 30. Qxc7+ — queen to c7 (capture) with check
- Ka8 — king to a8
- 31. Qxa7# — queen to a7 (capture) 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.
Corner mate
Driven into the corner, the king runs out of squares.
The corner mate catches a king driven into the corner, where it has only three neighboring squares — all of them taken away or blocked. The corner is the worst home for a king, because the attacker needs to control the fewest squares there. Herd the king toward the corner with checks and never let it slip back toward the center. Cut off the escape routes before the final check, and the mate practically assembles itself.
About this position
These pieces come from starting position #316.
SP-316 · ThroneScout — A knight starts on the edge (a/h) and the king sits centrally on d or e; the mirror twin stays in this family too.
The king starts on e1, the rooks on d1 and f1, the queen on c1.
The kingside rook already stands on f1, so castling short moves only the king, from e1 to g1.
The bishops stand on b1 and g1; their long diagonals reach h7 and a7 once the c- and f-pawns step aside.
One second-rank pawn starts with no defender at all: g2.
The setup belongs to the ThroneScout family; read right to left it becomes position 364.
The engine's main line opens with f4.
Morozov Balance Index: 2 of 100 — class D — largest edge. Engine evaluation of the starting position: +56 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #316Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-316
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