Starting position #559
Back-rank setup: RNKNQRBB
SP-559 · BastionGuard — The king starts one file off-centre, on c or f, with neither knight in a corner.
Move the pieces right on the board — full Chess960 rules, castle by dropping the king on the rook.
Position features
The king starts on c1, the rooks on a1 and f1, the queen on e1.
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.
The pawn on c2 is defended by the king alone — the same soft spot f2 is in the classical setup.
The setup belongs to the BastionGuard family; read right to left it becomes position 496.
The engine's main line opens with e4, putting a pawn straight into the centre.
Every sentence here is computed from the setup itself and can be checked on the board.
Balance
MBI 72 Morozov Balance Index: 72 of 100 — class B — balanced.
- Engine evaluation of the starting position: +20 centipawns for White (depth 43, 400 000 000 nodes).
- Rank 260 of 960 by balance — 1 is the most balanced start.
- Balance band S — slight edge · dynamics along the play-out: stable
- Evaluation along the engine's main line (60 half-moves): +35 → 0 → 0
Position facts
- Mirror twin: position #496
- The king starts on c, the rooks on a and f
- It becomes the daily position in 475 days
Puzzles from this position
- Attack on the uncastled king: queen to d3 (e2) — Chess960 specifics · 780
- Attack on the uncastled king: king to b2 (c1·3) — Chess960 specifics · 780
- Attack on the uncastled king: knight to b6 (c4) — Chess960 specifics · 920
- Winning blow: bishop to e1 (f2·2) — Chess960 specifics · 970
- Winning blow: queen to b7 (f3·3) — Chess960 specifics · 1150
- Winning blow: rook to a8 (b8) — Chess960 specifics · 1290
- Castling-960 to the rescue on f8 (c8) — Castling-960 · 1470
- Mate in 3: queen to b8 (b5) — Chess960 specifics · 1630
- Attack on the uncastled king: queen to f8 (f1·7) — Chess960 specifics · 1630
- Chess960 tactic on f8 (f4) — Chess960 specifics · 2120
This position appears in course day 21
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Commentary
Both castlings are half-moves here: the king already stands on c1 for the long one, and the rook already occupies f1 for the short. A bishop holds the corner on h1 with one diagonal to a8; the second bishop is on g1. The pawn on c2 leans on the king alone; no other second-rank pawn starts short of a defender. The queen is on e1, the knights on b1 and d1, the second rook in the corner on a1. The engine takes the centre with e4 and pushes it on: e4 g6 f4 f5 e5 d6.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.