Starting position #931
Back-rank setup: BRKRNQNB
SP-931 · BastionGuard — The king starts one file off-centre, on c or f, with neither knight in a corner.
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 b1 and d1, the queen on f1.
The king already stands on c1, so castling long moves only the rook, from b1 to d1.
A bishop starts in the corner on a1: it has a single diagonal, which the b-pawn unlocks, running out to h8.
The second rank carries 2 pawns with no defender at all: a2, h2.
The setup belongs to the BastionGuard family; read right to left it becomes position 19.
The engine's main line opens with g4.
Every sentence here is computed from the setup itself and can be checked on the board.
Balance
MBI 47 Morozov Balance Index: 47 of 100 — class C — noticeable edge.
- Engine evaluation of the starting position: +27 centipawns for White (depth 45, 400 000 000 nodes).
- Rank 492 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 (56 half-moves): +24 → 0 → 0
Position facts
- Mirror twin: position #19
- The king starts on c, the rooks on b and d
- King and rook are neighbours — castling from adjacent squares feels unusual
- It becomes the daily position in 65 days
Puzzles from this position
- Attack on the uncastled king: pawn to e4 (d3·7) — Chess960 specifics · 780
- Attack on the uncastled king: rook to a1 (b1) — Chess960 specifics · 780
- Attack on the uncastled king: queen to d5 (h1·3) — Chess960 specifics · 1010
- Winning blow: queen to f7 (h5·3) — Chess960 specifics · 1200
- Mate in 2: pawn to f4 (f2) — Chess960 specifics · 1220
- Castling-960 to the rescue on d8 (c8) — Castling-960 · 1340
- Winning blow: queen to a8 (a5·6) — Chess960 specifics · 1560
- Mate in 3: queen to a7 (f2·2) — Chess960 specifics · 1760
- Winning blow: knight to e5 (c6·4) — Chess960 specifics · 1870
- Chess960 tactic on g3 (f2) — Chess960 specifics · 2120
This position appears in course day 55
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Commentary
Both bishops start in the corners, on a1 and h1, each with a single long diagonal — one to h8, the other to a8. The king already stands on c1, so long castling moves the rook alone; the rooks are on b1 and d1. Two pawns begin without a defender, a2 and h2 — the edges of the rank. The queen is on f1, the knights on e1 and g1 — both can reach f3, so a knight move there has to name its file. White's edge is +27 centipawns, and the engine grabs space on the flank: g4 g6 f4 f5 g5 Nd6.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.