Winning blow: king to a2 (b1·11)
c9-15538naming 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.
Winning tactic: there is a move that gains a decisive advantage — find it.
Difficulty 970 ShuffleRating — for beginners taking their first steps in Chess960 tactics.
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 position hides a concrete tactic that wins material or mates. Start with the most forcing candidate moves — checks, captures and threats — and calculate each to a clear end before choosing; the winning line is usually the one the opponent cannot meet.
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 b1, queen d2, rook c1 a3, pawn e2 h2 g3 a4 c4 f4 d5.
Black: king a8, rook b6 d8, bishop g8 h8, pawn e4 g5 d6 c7 e7 h7.
11 white and 11 black pieces are on the board; the puzzle position arises after move 19.
The position in numbers
White are ahead by 4 points of material (26 against 22; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on b1, the black king on a8.
It is White to move on move 19, with 5 legal replies to weigh — only the line that keeps the advantage solves the puzzle. White are in check right now, so every reply must answer the check.
White keeps 7 pawns, Black 6. Files fully open (no pawns of either colour): b — natural highways for the rooks and queen.
Black hold the bishop pair, an edge in open lines. 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
19. Ka2 Rdb8 20. Rb3 Rxb3 21. Qa5+
Why it works
- Great move! king to a2 keeps the pressure (+4.1).
- rook to b3 develops smoothly.
- Strong! queen to a5 is the sharp choice (+4.6).
- You reach a winning position (+4.6).
- If instead Rdb8, then Qa5+ and you stay on top.
Move by move
- 19. Ka2 — king to a2
Types in this puzzle
Winning blow
Find the strike that wins material by force.
A winning blow is a forced material gain that does not fit a single textbook motif. The general tactical recipe applies: spot loose pieces, an awkwardly placed king, overloaded lines. Go through the forcing moves in order of violence — checks, captures, threats — because most combinations start with one of them. Do not judge by feel: calculate the concrete line until the outcome is beyond doubt.
Only move
Everything else loses — find the only move that holds.
An only move is a position where everything loses except one single continuation. You cannot play "by hand" here: run through fundamentally different defenses — run away, block, trade, counterattack — and discard the ones that fail. The hallmark of these puzzles is that the obvious moves lose quickly while the solution often looks strange. First understand exactly what the threat is — then the one saving move reveals itself.
About this position
These pieces come from starting position #927.
SP-927 · 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 c1, 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.
The pawn on b2 is defended by the king alone — the same soft spot f2 is in the classical setup.
The setup belongs to the RampartGuard family; read right to left it becomes position 32.
The engine's main line opens with a4.
Morozov Balance Index: 3 of 100 — class D — largest edge. Engine evaluation of the starting position: +52 centipawns for White (depth 46, 400 000 000 nodes).
Explore position #927Provenance
Mined from the project's engine self-play games.
Pack 005 · SP-927
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads