Chess960 tactic on b7 (d7)
c9-28514naming 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: 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 2400 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 b2, rook d7 h7, bishop e4, pawn c2 b4.
Black: king b8, rook e8, pawn a4 f4 b5 d6.
6 white and 6 black pieces are on the board; the puzzle position arises after move 37.
The position in numbers
White are ahead by 6 points of material (15 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 b2, the black king on b8.
It is White to move on move 37, with 36 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 2 pawns, Black 4. Files fully open (no pawns of either colour): e, g, h — natural highways for the rooks and queen. Half-open for White: a, d, f.
The White king has 6 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
37. Rb7+ Kc8 38. Bf5+ Re6 39. Bxe6+ Kd8 40. Rb8#
Why it works
- Best move. rook to b7 is exactly what the engine plays (#3).
- Spot on — bishop to f5 (#2).
- Precise: bishop to e6 is the top choice (#1).
- Best move. rook to b8 is exactly what the engine plays (#).
- The line ends in a forced mate in 4.
- If instead Kc8, then Bf5+ and you stay on top.
Move by move
- 37. Rb7+ — rook to b7 with check
- Kc8 — king to c8
- 38. Bf5+ — bishop to f5 with check
- Re6 — rook to e6
- 39. Bxe6+ — bishop to e6 (capture) with check
- Kd8 — king to d8
- 40. Rb8# — rook to b8 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 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.
Endgame tactic
Tactics live in the endgame too — strike while material is scarce.
Tactics do not retire when the queens come off: forks, pins and double attacks live on in the endgame. With so little material left, every tactical loss is almost always decisive. The signs are the usual ones — undefended pieces, king and piece on one line, a pawn about to promote. Even in a "technical" ending, scan for a shot before every move, both yours and your opponent's.
About this position
These pieces come from starting position #903.
SP-903 · RampartGuard — King pushed to the b- or g-file, knights off the edges — 144 positions here.
The king starts on b1, the rooks on a1 and e1, the queen on d1.
From b1 the king makes the longest journey Chess960 allows when castling short: five squares to g1.
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 RampartGuard family; read right to left it becomes position 50.
The engine's main line opens with d4, putting a pawn straight into the centre.
Morozov Balance Index: 14 of 100 — class D — largest edge. Engine evaluation of the starting position: +40 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #903Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-903
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads