Starting position #802
Back-rank setup: BRKQNBRN
SP-802 · 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 b1 and g1, the queen on d1.
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 BastionScout family; read right to left it becomes position 151.
The engine's main line opens with e3.
Every sentence here is computed from the setup itself and can be checked on the board.
Balance
MBI 86 Morozov Balance Index: 86 of 100 — class A — most balanced.
- Engine evaluation of the starting position: +15 centipawns for White (depth 43, 400 000 000 nodes).
- Rank 123 of 960 by balance — 1 is the most balanced start.
- Balance band S — slight edge · dynamics along the play-out: equalizing
- Evaluation along the engine's main line (70 half-moves): +16 → -14 → 0 → 0
- Deeper check (1 200 000 000 nodes, depth 49): +18 cp, +3 cp against the base run — verified
Position facts
- Mirror twin: position #151
- The king starts on c, the rooks on b and g
- King and rook are neighbours — castling from adjacent squares feels unusual
- It becomes the daily position in 280 days
Puzzles from this position
- Attack on the uncastled king: king to a2 — Chess960 specifics · 780
- Winning blow: bishop to f6 (a1·5) — Chess960 specifics · 920
- Winning blow: knight to d7 (f6·6) — Chess960 specifics · 920
- Winning blow: knight to h5 (g7·2) — Chess960 specifics · 970
- Winning blow: pawn to a7 (a6·3) — Chess960 specifics · 1110
- Winning blow: rook to a7 (a4) — Chess960 specifics · 1200
- Winning blow: queen to d8 (e8·3) — Chess960 specifics · 1340
- Mate in 3: rook to b4 (b3) — Chess960 specifics · 1630
- Winning blow: queen to a7 (a4·4) — Chess960 specifics · 1870
- Winning blow: queen to c6 (c2·5) — Chess960 specifics · 2100
This position appears in course day 69
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Commentary
The queen keeps her classical square d1, but the king stands to her left, on c1, so long castling moves the rook alone. A bishop holds the corner on a1 with one diagonal to h8; the second bishop is on f1. Two pawns begin without a defender, a2 and h2 — the edges of the rank. The knights are on e1 and h1 — the cornered one has g3 as its only move, and the rooks are on b1 and g1. White's edge is a narrow +15 centipawns: e3 e6 g4 g5 Ng3 Ng6.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.