Starting position #489
Back-rank setup: QRNBBKNR
SP-489 · 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 f1, the rooks on b1 and h1, the queen on a1.
Castling ends where it always does: king to g1 and rook to f1 on the short side, king to c1 and rook to d1 on the long one.
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 g2 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 569.
The engine's main line opens with b4.
Every sentence here is computed from the setup itself and can be checked on the board.
Balance
MBI 97 Morozov Balance Index: 97 of 100 — class A — most balanced.
- Engine evaluation of the starting position: +7 centipawns for White (depth 45, 400 000 000 nodes).
- Rank 27 of 960 by balance — 1 is the most balanced start.
- Balance band E — even · dynamics along the play-out: stable
- Evaluation along the engine's main line (68 half-moves): +33 → +14 → 0 → 0
- Deeper check (1 200 000 000 nodes, depth 48): +18 cp, +11 cp against the base run — not confirmed at depth · S — slight edge
Position facts
- Mirror twin: position #569
- The king starts on f, the rooks on b and h
- This position does not come up as the daily position in the next four years
Puzzles from this position
- Winning blow: queen to c3 — Chess960 specifics · 780
- Attack on the uncastled king: pawn to d5 (c4·31) — Chess960 specifics · 780
- Attack on the uncastled king: knight to g5 (f3·13) — Chess960 specifics · 780
- Attack on the uncastled king: pawn to g4 (f3·24) — Chess960 specifics · 780
- Winning blow: knight to b3 — Chess960 specifics · 970
- Attack on the uncastled king: bishop to d6 (g3·6) — Chess960 specifics · 1060
- Mate in 2: queen to d8 (d7·2) — Chess960 specifics · 1320
- Castling-960 to the rescue on h1 (f1·4) — Castling-960 · 1340
- Mate in 3: rook to e7 (e6·3) — Chess960 specifics · 1760
- Chess960 tactic on d8 (c8) — Chess960 specifics · 2250
This position appears in course day 24
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Commentary
The engine finds very little here — +7 centipawns. Castling is ordinary in both directions from f1, with the rooks on b1 and h1. The bishops stand side by side on d1 and e1, one on each colour. On the second rank, g2 leans on the king alone; no other second-rank pawn starts short of a defender. The queen begins in the far corner on a1, the knights on c1 and g1, and the line runs b4 a5 b5 d5 Nf3 c6.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.