Mate in 3: queen to c3 (a1)
c9-24755naming 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 d1, queen a1, rook b1 e1, bishop h1 e5, knight g1 e3, pawn a2 c2 d2 e2 h2 g3 f4.
Black: king c8, queen a8, rook b8 e8, bishop f5 h8, knight f6, pawn a6 g6 b7 e7 f7 h7.
15 white and 13 black pieces are on the board; the puzzle position arises after move 10.
The position in numbers
White are ahead by 4 points of material (38 against 34; 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 10, with 43 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 7 pawns, Black 6. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: b.
The White king has 2 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
10. Qc3+ Kd7 11. Qc7+ Ke6 12. Rb6#
Why it works
- Great move! queen to c3 keeps the pressure (#2).
- Spot on — queen to c7 (#1).
- Precise: rook to b6 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Kd7, then Qc7+ and you stay on top.
Move by move
- 10. Qc3+ — queen to c3 with check
- Kd7 — king to d7
- 11. Qc7+ — queen to c7 with check
- Ke6 — king to e6
- 12. Rb6# — rook to b6 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.
Development punish
Half the army still asleep — the attack breaks through.
Punishing lazy development: half of your opponent's army is asleep on its starting squares, which means you outnumber him where the fight is. Count not the pieces on the board but the pieces in play — if five or more of his pieces have never moved, look for a forcing attack. The sign is a development lead plus open lines toward his king. Strike immediately: give him two quiet moves and the advantage evaporates.
About this position
These pieces come from starting position #871.
SP-871 · ThroneGuard — A central king (d or e) and two knights tucked onto inner files: the family that holds the standard array, SP-518.
The king starts on d1, the rooks on b1 and e1, the queen on a1.
Castling ends where it always does: king to g1 and rook to f1 on the short side, king to c1 and rook to d1 on the long one.
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: f2.
The setup belongs to the ThroneGuard family; read right to left it becomes position 82.
The engine's main line opens with b4.
Morozov Balance Index: 43 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +28 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #871Provenance
Mined from the project's engine self-play games.
Pack 012 · SP-871
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