Starting position #707
Back-rank setup: BRKQNNRB
SP-707 · BastionGuard — Off-centre king (c/f), no knight on the a- or h-file.
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, f2.
The setup belongs to the BastionGuard family; read right to left it becomes position 435.
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 20 Morozov Balance Index: 20 of 100 — class D — largest edge.
- Engine evaluation of the starting position: +37 centipawns for White (depth 44, 400 000 000 nodes).
- Rank 767 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): +26 → +31 → 0
Position facts
- Mirror twin: position #435
- The king starts on c, the rooks on b and g
- 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: queen to b5 — Chess960 specifics · 780
- Attack on the uncastled king: king to c3 — Chess960 specifics · 780
- Attack on the uncastled king: pawn to g5 (f4·20) — Chess960 specifics · 780
- Winning blow: rook to d4 (d1·2) — Chess960 specifics · 920
- Winning blow: king to d1 (c2·3) — Chess960 specifics · 970
- Mate in 2: knight to b6 (c4) — Chess960 specifics · 1090
- Attack on the uncastled king: queen to a5 (a6·3) — Chess960 specifics · 1250
- Mate in 2: queen to e8 (a4·2) — Chess960 specifics · 1670
- Winning blow: queen to e5 (g3·4) — Chess960 specifics · 1870
- Mate in 3: knight to b3 — Chess960 specifics · 2170
This position appears in course day 43
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Commentary
Both corners hold a bishop, a1 towards h8 and h1 towards a8, each with a single diagonal — and in the engine's line the first one goes the whole way: after b4 b6 c4 g6 comes Bxh8, and a rook takes back: Rxh8. The king already stands on c1, so long castling moves the rook alone from b1. Two pawns begin with no defender at all: a2 and f2. The queen is on d1 beside her king, the knights side by side on e1 and f1. The second rook stands on g1.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.