Starting position #255
Back-rank setup: NRKQNRBB
SP-255 · BastionScout — Off-centre king plus a rim knight (a/h): 168 positions carry this shape.
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 b1 and f1, the queen on d1.
The king already stands on c1, so castling long moves only the rook, from b1 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: a2.
The setup belongs to the BastionScout family; read right to left it becomes position 608.
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 83 Morozov Balance Index: 83 of 100 — class A — most balanced.
- Engine evaluation of the starting position: +16 centipawns for White (depth 44, 400 000 000 nodes).
- Rank 174 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): +34 → +28 → 0
Position facts
- Mirror twin: position #608
- The king starts on c, the rooks on b and f
- King and rook are neighbours — castling from adjacent squares feels unusual
- It becomes the daily position in 630 days
Puzzles from this position
- Attack on the uncastled king: king to b1 — Chess960 specifics · 780
- Winning blow: queen to d6 (e7) — Chess960 specifics · 920
- Winning blow: bishop to b6 (g1) — Chess960 specifics · 920
- Winning blow: knight to c5 (d7) — Chess960 specifics · 970
- Mate in 2: rook to c5 — Chess960 specifics · 1220
- Winning blow: queen to b4 (b3·2) — Chess960 specifics · 1420
- Mate in 2: queen to c7 (c2·3) — Chess960 specifics · 1450
- Mate in 3: pawn to b5 (c4) — Chess960 specifics · 1630
- Winning blow: pawn to f7 (f6·15) — Chess960 specifics · 1750
- Chess960 tactic on c5 (d4) — Chess960 specifics · 2120
This position appears in course day 66
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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. A knight begins in the corner on a1 with b3 as its only move, the second on e1. Among the pawns, a2 starts without a defender. The engine sees little for White — +16 centipawns — and its line runs f4 f5 b3 Nb6 c4 d6.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.