Mate in 3: pawn to c8 (b7)
c9-26626naming 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 1760 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 g1, bishop f1 a3, knight c2 e7, pawn g3 f4 h4 b7.
Black: king g7, rook c8, pawn e4 f5 h5 g6.
9 white and 6 black pieces are on the board; the puzzle position arises after move 41.
The position in numbers
White are ahead by 7 points of material (16 against 9; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on g1, the black king on g7.
It is White to move on move 41, with 36 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): a, c, d — natural highways for the rooks and queen. Half-open for White: e.
White hold the bishop pair, an edge in open lines. 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
41. bxc8=Q Kf6 42. Qg8 e3 43. Qxg6#
Why it works
- Best move. pawn to c8 is exactly what the engine plays (#2).
- queen to g8 develops smoothly.
- Precise: queen to g6 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Kf6, then Qg8 and you win the rook.
Move by move
- 41. bxc8=Q — pawn to c8 (capture)
- Kf6 — king to f6
- 42. Qg8 — queen to g8
- e3 — pawn to e3
- 43. Qxg6# — queen to g6 (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.
Promotion race
Both sides push passers — win the race by a tempo.
A promotion race is a sprint between two passed pawns: both sides push toward the last rank, and victory goes to whoever queens first or queens with check. You will recognize it when both players have far-advanced passers that neither king can catch. Count the tempi literally, move by move, all the way to promotion. The classic mistake is spending a tempo on a "useful" move — in a race, almost any non-pawn move loses.
About this position
These pieces come from starting position #10.
SP-10 · RampartGuard — Both knights begin on inner files while the king sits on the wing (b/g); mirror twins stay together in this family.
The king starts on g1, the rooks on d1 and h1, the queen on a1.
The king already stands on its castled square, so castling short moves only the rook, from h1 to f1.
The bishops stand on e1 and f1; their long diagonals reach a5 and a6 once the d- and e-pawns step aside.
One second-rank pawn starts with no defender at all: c2.
The setup belongs to the RampartGuard family; read right to left it becomes position 949.
The engine's main line opens with c4.
Morozov Balance Index: 31 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +32 centipawns for White (depth 49, 400 000 000 nodes).
Explore position #10Provenance
Mined from the project's engine self-play games.
Pack 013 · SP-10
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