Chess960 tactic on a5
c9-15632Opens 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 f2, queen c3, bishop c6, pawn g2.
Black: king d8, queen h6, bishop d6, pawn b5 e7 h7.
4 white and 6 black pieces are on the board; the puzzle position arises after move 37.
The position in numbers
Black are ahead by 2 points of material (13 against 15; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on f2, the black king on d8.
It is White to move on move 37, with 37 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 1 pawns, Black 3. Files fully open (no pawns of either colour): a, c, d, f — natural highways for the rooks and queen. Half-open for White: b, e, h.
The White king has 5 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
37. Qa5+ Kc8 38. Qa8+ Kc7 39. Qb7+ Kd8 40. Qd7#
Why it works
- Great move! queen to a5 keeps the pressure (#3).
- Spot on — queen to a8 (#2).
- Strong! queen to b7 is the sharp choice (#1).
- Best move. queen to d7 is exactly what the engine plays (#).
- The line ends in a forced mate in 4.
- If instead Kc8, then Qa8+ and you stay on top.
Move by move
- 37. Qa5+ — queen to a5 with check
- Kc8 — king to c8
- 38. Qa8+ — queen to a8 with check
- Kc7 — king to c7
- 39. Qb7+ — queen to b7 with check
- Kd8 — king to d8
- 40. Qd7# — queen to d7 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 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.
Queen endgame
Queens on an open board — precision above all.
Queen endgames are treacherous: the queen reaches everywhere, and one slip turns a win into perpetual check. The signs are few pawns, exposed kings, and checks hanging in the air. Tuck your king away early, and use your own checks to bring the queen closer or push your passer with tempo. The typical mistake is grabbing pawns while leaving your king exposed to endless checks.
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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