Winning blow: rook to b5 (a5·2)
c9-09605naming 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 1430 ShuffleRating — club-player level.
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 c1, queen c5, rook f1 a5, bishop g3, knight b3, pawn b2 e2 h2.
Black: king b7, queen g8, rook a8 f8, bishop c6 h8, knight e4, pawn g4 f5 g6 a7 c7.
9 white and 12 black pieces are on the board; the puzzle position arises after move 19.
The position in numbers
Black are ahead by 5 points of material (28 against 33; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on c1, the black king on b7.
It is White to move on move 19, with 51 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 3 pawns, Black 5. Files fully open (no pawns of either colour): d — natural highways for the rooks and queen. Half-open for White: a, c, f, g.
Black 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
19. Rb5+ Kc8 20. Qxc6 Nxg3 21. Qxa8+ Kd7 22. Rd1+
Why it works
- Great move! rook to b5 keeps the pressure (+6.4).
- Well found: queen to c6 (+6.5).
- Precise: queen to a8 is the top choice (+5.5).
- Great move! rook to d1 keeps the pressure (+5.7).
- You win a piece — the rook.
- If instead Kc8, then Qxc6 and you win the bishop.
Move by move
- 19. Rb5+ — rook to b5 with check
- Kc8 — king to c8
- 20. Qxc6 — queen to c6 (capture)
- Nxg3 — knight to g3 (capture)
- 21. Qxa8+ — queen to a8 (capture) with check
- Kd7 — king to d7
- 22. Rd1+ — rook to d1 with check
Types in this puzzle
Overload
One defender guards two things — it cannot do both jobs.
Overloading exploits a defender with two jobs at once — guarding a piece and covering a mating square, for instance. It cannot do both: your first strike forces it to handle one duty and abandon the other. Find the overworked piece by asking what happens to each of its charges if it gets distracted. Then hit one target and collect the other — an overloaded defender only pretends to defend.
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.
Counter-strike
Don't defend — answer the threat with a bigger one.
The counter-strike: instead of defending against the threat, you answer with a bigger threat of your own. While your opponent grabs a pawn, you deliver mate — the arithmetic favors you. Look for a counter when direct defenses fail: do you have a check, an attack on the queen, a mating threat? The beginner's error is meeting every threat with a reflexive defense without checking the counterattacking resources first.
About this position
These pieces come from starting position #571.
SP-571 · BastionGuard — The king starts one file off-centre, on c or f, with neither knight in a corner.
The king starts on c1, the rooks on a1 and f1, the queen on g1.
The king already stands on c1, so castling long moves only the rook, from a1 to d1.
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: e2.
The setup belongs to the BastionGuard family; read right to left it becomes position 481.
The engine's main line opens with f4.
Morozov Balance Index: 65 of 100 — class B — balanced. Engine evaluation of the starting position: +22 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #571Provenance
Mined from the project's engine self-play games.
Pack 010 · SP-571
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