Starting position #669
Back-rank setup: RNKBRNBQ
SP-669 · BastionGuard — King shifted to c or f, knights kept clear of the edges — 168 positions in all.
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 e1, 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 d1 and g1; their long diagonals reach h5 and a7 once the e- 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 BastionGuard family; read right to left it becomes position 200.
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 5 Morozov Balance Index: 5 of 100 — class D — largest edge.
- Engine evaluation of the starting position: +49 centipawns for White (depth 45, 400 000 000 nodes).
- Rank 914 of 960 by balance — 1 is the most balanced start.
- Balance band L — large edge · dynamics along the play-out: stable
- Evaluation along the engine's main line (60 half-moves): +37 → +61 → +36 → +5
Position facts
- Mirror twin: position #200
- The king starts on c, the rooks on a and e
- This position does not come up as the daily position in the next four years
Puzzles from this position
- Attack on the uncastled king: rook to a4 (a1) — Chess960 specifics · 780
- Attack on the uncastled king: bishop to e2 (d1) — Chess960 specifics · 780
- Attack on the uncastled king: queen to c6 (h1·5) — Chess960 specifics · 920
- Winning blow: king to c1 (b1) — Chess960 specifics · 970
- Attack on the uncastled king: pawn to b5 (b4·4) — Chess960 specifics · 1110
- Winning blow: queen to a8 (h1·4) — Chess960 specifics · 1200
- Winning blow: rook to b7 (b8·3) — Chess960 specifics · 1390
- Mate in 3: rook to b6 (d6) — Chess960 specifics · 1630
- Winning blow: rook to d4 (d2·3) — Chess960 specifics · 1750
- Chess960 tactic on e6 (d5·4) — Chess960 specifics · 2400
This position appears in course day 72
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Commentary
The king already stands on c1, so long castling moves the rook alone from a1. The bishops are on d1 and g1, the knights on b1 and f1. On the second rank, b2 leans on the king alone; no other second-rank pawn starts short of a defender. The queen begins in the far corner on h1, the second rook on e1. White's edge here is a wide one, +49 centipawns: e4 e5 g3 Nc6 Nc3 a5.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.