Starting position #940
Back-rank setup: RBKRNQBN
SP-940 · BastionScout — A knight on the a- or h-file, king on c or f — the mirror twin lands here as well.
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 d1, the queen on f1.
The king already stands on c1, so castling long moves only the rook, from a1 to d1.
The bishops stand on b1 and g1; their long diagonals reach h7 and a7 once the c- and f-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 28.
The engine's main line opens with a4.
Every sentence here is computed from the setup itself and can be checked on the board.
Balance
MBI 59 Morozov Balance Index: 59 of 100 — class B — balanced.
- Engine evaluation of the starting position: +24 centipawns for White (depth 49, 400 000 000 nodes).
- Rank 382 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 → +15 → 0
Position facts
- Mirror twin: position #28
- The king starts on c, the rooks on a and d
- King and rook are neighbours — castling from adjacent squares feels unusual
- It becomes the daily position in 505 days
Puzzles from this position
- Attack on the uncastled king: pawn to d5 (e4·58) — Chess960 specifics · 780
- Mate in 2: queen to c7 (c6) — Chess960 specifics · 1090
- Winning blow: king to f2 (e1·12) — Chess960 specifics · 1110
- Winning blow: pawn to f5 (g4·10) — Chess960 specifics · 1200
- Winning blow: knight to d7 (e5·12) — Chess960 specifics · 1280
- Mate in 2: rook to a6 (c6) — Chess960 specifics · 1320
- Mate in 3: queen to c7 (d7) — Chess960 specifics · 1630
- Mate in 3: queen to e7 (c5·5) — Chess960 specifics · 1630
- Mate in 3: rook to d7 (d6·2) — Chess960 specifics · 1980
- Chess960 tactic on e8 (c6) — Chess960 specifics · 2400
This position appears in course day 105
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Commentary
The king already stands on c1, so long castling moves the rook alone; the rooks are on a1 and d1. The bishops are on b1 and g1, one on each colour. Among the pawns, b2 leans on the king alone; no other second-rank pawn starts short of a defender. The queen is on f1, the knights on e1 and h1 — the cornered one has g3 as its only move. The search ran to depth 49 and calls it +24 centipawns, with Black's queen recapturing in the centre: a4 a5 e4 f5 exf5 Qxf5.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.