Chess960 tactic on a4
c9-11210Opens in the app if installed, otherwise downloads the APK.
The tactical motive
Chess960 twist: use the unusual starting setup of the pieces.
Mate: a forcing sequence that ends the game — the king has no escape.
Mate in 4: a forced checkmate in four moves — every reply is covered.
Difficulty 2120 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.
This is a forced mating attack. Start from the enemy king: which of its squares are already covered, and which move takes away the rest while keeping the king in check? Forcing moves — checks and captures — are what turn an attack into mate.
A mate in four is a longer forced net: each of your moves is a check or an irresistible threat, and the king is driven step by step to a square where it is finally trapped. Verify that the defender has exactly one reply at every branch.
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 f3, rook g5, bishop e4, knight h2, pawn a2 f2 b3 h4 c5 h5.
Black: king h8, rook a4, pawn f4 e5 b7.
10 white and 5 black pieces are on the board; the puzzle position arises after move 32.
The position in numbers
White are ahead by 9 points of material (17 against 8; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on f3, the black king on h8.
It is White to move on move 32, with 28 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 3. Files fully open (no pawns of either colour): d, g — natural highways for the rooks and queen. Half-open for White: 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
32. bxa4 b5 33. c6 b4 34. c7 b3 35. c8=Q#
Why it works
- Best move. pawn to a4 is exactly what the engine plays (#3).
- pawn to c6 develops smoothly.
- A natural move: pawn to c7.
- Best move. pawn to c8 is exactly what the engine plays (#).
- The line ends in a forced mate in 4.
- If instead b5, then c6 and you win the rook.
Move by move
- 32. bxa4 — pawn to a4 (capture)
- b5 — pawn to b5
- 33. c6 — pawn to c6
- b4 — pawn to b4
- 34. c7 — pawn to c7
- b3 — pawn to b3
- 35. c8=Q# — pawn to c8 and it is checkmate
Types in this puzzle
Promotion mate
The pawn promotes — and the new piece mates on the spot.
In a promotion mate the pawn takes its final step and the newborn piece mates on the spot. Sometimes the hero is a knight rather than a queen — it checks from the promotion square in a way no queen can. The sign: the enemy king lingers near the promotion square while your pieces already control its escape routes. When counting pawn races, always check whether the promotion itself is mate — that gains you a full tempo in the evaluation.
Mate in 4+
A long forced mating combination.
Mate in four or longer is a marathon of forcing moves where the grip must never loosen. The tools are the same: checks, double threats and sacrifices that deny the opponent a single free tempo. Do not juggle the whole tree at once — walk the main line all the way to mate first, then verify the side branches. If somewhere the defender finds one quiet move that holds, your very first move was wrong.
Passed pawn
Nothing can stop the passer — escort it to the last rank.
A passed pawn has no enemy pawns in front of it or on the neighboring files: only pieces can stop it. Check who can blockade the pawn or catch it with the king — if nobody can, the pawn is worth a whole piece. Push the passer with your pieces supporting it, and put your rook behind it. The beginner's mistake is shoving the pawn forward unprotected, straight into a capture.
About this position
These pieces come from starting position #404.
SP-404 · RampartGuard — A b- or g-file king and two knights on inner files (b–g).
The king starts on g1, the rooks on a1 and h1, the queen on d1.
The king already stands on its castled square, so castling short moves only the rook, from h1 to f1.
The bishops stand on b1 and c1; their long diagonals reach h7 and h6 once the c- and d-pawns step aside.
The pawn on f2 is defended by the king alone — the classic soft spot of the standard setup.
The setup belongs to the RampartGuard family; read right to left it becomes position 750.
The engine's main line opens with e4, putting a pawn straight into the centre.
Morozov Balance Index: 83 of 100 — class A — most balanced. Engine evaluation of the starting position: +16 centipawns for White (depth 47, 400 000 000 nodes).
Explore position #404Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-404
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads