Starting position #952
Back-rank setup: RBKRBNNQ
SP-952 · BastionGuard — Both knights begin inside the board while the king stands on c or f; a position and its mirror twin share this family.
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 h1.
The king already stands on c1, so castling long moves only the rook, from a1 to d1.
The bishops stand on b1 and e1; their long diagonals reach h7 and a5 once the c- 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 BastionGuard family; read right to left it becomes position 13.
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 16 Morozov Balance Index: 16 of 100 — class D — largest edge.
- Engine evaluation of the starting position: +39 centipawns for White (depth 43, 400 000 000 nodes).
- Rank 797 of 960 by balance — 1 is the most balanced start.
- Balance band M — moderate edge · dynamics along the play-out: stable
- Evaluation along the engine's main line (60 half-moves): +38 → +35 → +13 → -8
Position facts
- Mirror twin: position #13
- The king starts on c, the rooks on a and d
- King and rook are neighbours — castling from adjacent squares feels unusual
- This position does not come up as the daily position in the next four years
Puzzles from this position
- Attack on the uncastled king: pawn to d5 (c4·22) — Chess960 specifics · 780
- Attack on the uncastled king: king to b2 (c1·5) — Chess960 specifics · 780
- Winning blow: pawn to c3 (b2·11) — Chess960 specifics · 920
- Attack on the uncastled king: queen to g8 (d5·2) — Chess960 specifics · 1090
- Winning blow: knight to f2 (h3) — Chess960 specifics · 1200
- Winning blow: rook to e3 (d3·2) — Chess960 specifics · 1280
- Mate in 2: knight to b6 (d5·3) — Chess960 specifics · 1450
- Mate in 3: rook to e8 (e2·2) — Chess960 specifics · 1630
- Attack on the uncastled king: bishop to a6 (c4·4) — Chess960 specifics · 1630
- Chess960 tactic on f6 — Chess960 specifics · 2120
This position appears in course day 93
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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 queen begins in the corner on h1. The bishops are on b1 and e1, one on each colour. Among the pawns, b2 leans on the king alone; no other second-rank pawn starts short of a defender. The knights are on f1 and g1, and their reaches do not overlap, so the line writes Ne3 with no file letter. The engine takes the centre with e4, and White's edge is +39 centipawns: e4 e5 c3 Ne6 Ne3 g6.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.