Starting position #649
Back-rank setup: RNKBBRQN
SP-649 · BastionScout — A c- or f-file king with at least one knight out on the edge.
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.
The bishops stand on d1 and e1; their long diagonals reach h5 and a5 once the e- and d-pawns step aside.
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 BastionScout family; read right to left it becomes position 217.
The engine's main line opens with g4.
Every sentence here is computed from the setup itself and can be checked on the board.
Balance
MBI 75 Morozov Balance Index: 75 of 100 — class B — balanced.
- Engine evaluation of the starting position: +19 centipawns for White (depth 48, 400 000 000 nodes).
- Rank 232 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): +31 → +10 → 0
Position facts
- Mirror twin: position #217
- The king starts on c, the rooks on a and f
- It becomes the daily position in 109 days
Puzzles from this position
- Attack on the uncastled king: pawn to d4 (e3·4) — Chess960 specifics · 780
- Attack on the uncastled king: knight to g7 (h5·4) — Chess960 specifics · 780
- Winning blow: knight to f1 — Chess960 specifics · 780
- Winning blow: knight to d5 (c3·3) — Chess960 specifics · 920
- Winning blow: knight to c4 (b6·2) — Chess960 specifics · 1110
- Winning blow: knight to b5 (d6·7) — Chess960 specifics · 1280
- Mate in 2: queen to b7 (h1·2) — Chess960 specifics · 1450
- Mate in 3: rook to b5 (a5) — Chess960 specifics · 1630
- Winning blow: pawn to g3 (g2·7) — Chess960 specifics · 1750
- Winning blow: rook to c5 (c1·18) — Chess960 specifics · 2290
This position appears in course day 61
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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. The bishops stand side by side on d1 and e1, one on each colour. The pawn on b2 leans on the king alone; no other second-rank pawn starts short of a defender. The queen is on g1, the knights on b1 and h1 — the cornered one has g3 as its only move. The search ran to depth 48 and calls it +19 centipawns: g4 g5 e3 Nc6 h4 gxh4.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.