Starting position #571
Back-rank setup: RNKNBRQB
SP-571 · 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 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.
Every sentence here is computed from the setup itself and can be checked on the board.
Balance
MBI 65 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).
- Rank 337 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): +32 → +36 → 0
Position facts
- Mirror twin: position #481
- The king starts on c, the rooks on a and f
- It becomes the daily position in 302 days
Puzzles from this position
- Attack on the uncastled king: queen to f7 (f1) — Chess960 specifics · 780
- Attack on the uncastled king: queen to c6 (g2·2) — Chess960 specifics · 920
- Winning blow: bishop to a6 (b5) — Chess960 specifics · 970
- Winning blow: knight to f6 (e4·14) — Chess960 specifics · 1200
- Attack on the uncastled king: queen to g2 (g1·8) — Chess960 specifics · 1250
- Winning blow: pawn to e6 (d5·19) — Chess960 specifics · 1280
- Winning blow: rook to b5 (a5·2) — Chess960 specifics · 1430
- Attack on the uncastled king: rook to f6 (f4) — Chess960 specifics · 1510
- Mate in 2: queen to e7 (g5·5) — Chess960 specifics · 1630
- Winning blow: rook to c7 (c5·2) — Chess960 specifics · 1790
This position appears in course day 57
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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 e1. The pawn on e2 has no defender, and c2 leans on the king alone. The queen is on g1, the knights on b1 and d1, the second rook in the corner on a1. The published line opens f4 f5, then Nbc3 d6 g4 fxg4.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.