Starting position #637
Back-rank setup: RNKBQRBN
SP-637 · 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 e1.
The king already stands on c1, so castling long moves only the rook, from a1 to d1.
The bishops stand on d1 and g1; their long diagonals reach h5 and a7 once the e- and f-pawns step aside.
One second-rank pawn starts with no defender at all: g2.
The setup belongs to the BastionScout family; read right to left it becomes position 232.
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 39 Morozov Balance Index: 39 of 100 — class C — noticeable edge.
- Engine evaluation of the starting position: +21 centipawns for White (depth 44, 400 000 000 nodes).
- Rank 588 of 960 by balance — 1 is the most balanced start.
- In 50 self-play games White scored 57.0% (95% CI 43.3–69.7%).
- Balance band S — slight edge · dynamics along the play-out: equalizing
- Evaluation along the engine's main line (52 half-moves): +52 → +40 → 0
Position facts
- Mirror twin: position #232
- The king starts on c, the rooks on a and f
- It becomes the daily position in 161 days
Puzzles from this position
- Attack on the uncastled king: pawn to f5 (e4) — Chess960 specifics · 780
- Attack on the uncastled king: pawn to d3 (c2·7) — Chess960 specifics · 780
- Attack on the uncastled king: bishop to e3 (g1·6) — Chess960 specifics · 970
- Winning blow: queen to c5 (e3) — Chess960 specifics · 1060
- Winning blow: bishop to d5 (e4·3) — Chess960 specifics · 1150
- Winning blow: queen to f5 (f2·3) — Chess960 specifics · 1200
- Winning blow: knight to d6 (b5·15) — Chess960 specifics · 1290
- Attack on the uncastled king: knight to g7 (f5·23) — Chess960 specifics · 1610
- Mate in 3: rook to d7 (e7) — Chess960 specifics · 1760
- Winning blow: queen to f8 (c5) — Chess960 specifics · 1870
This position appears in course day 18
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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 are on d1 and g1, the knights on b1 and h1 — the cornered one has g3 as its only move. The pawn on g2 has no defender, and b2 leans on the king alone. The queen is on e1, the second rook in the corner on a1. The engine takes the centre with e4 and the kingside opens up: e4 f5 exf5 g6 g4 gxf5.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.