Starting position #723
Back-rank setup: BRKNQNRB
SP-723 · 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 b1 and g1, the queen on e1.
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.
One second-rank pawn starts with no defender at all: a2.
The setup belongs to the BastionGuard family; read right to left it becomes position 419.
The engine's main line opens with g3.
Every sentence here is computed from the setup itself and can be checked on the board.
Balance
MBI 43 Morozov Balance Index: 43 of 100 — class C — noticeable edge.
- Engine evaluation of the starting position: +28 centipawns for White (depth 47, 400 000 000 nodes).
- Rank 537 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 (40 half-moves): +25 → 0
Position facts
- Mirror twin: position #419
- 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 411 days
Puzzles from this position
- Attack on the uncastled king: rook to e8 (e5) — Chess960 specifics · 620
- Attack on the uncastled king: pawn to c6 (b5·10) — Chess960 specifics · 780
- Winning blow: rook to c7 (g7) — Chess960 specifics · 1010
- Winning blow: knight to e7 (d5·16) — Chess960 specifics · 1060
- Mate in 2: rook to a6 (d6) — Chess960 specifics · 1220
- Winning blow: pawn to f8 (f7) — Chess960 specifics · 1280
- Winning blow: rook to e7 (e2·2) — Chess960 specifics · 1390
- Winning blow: queen to g4 (e2·3) — Chess960 specifics · 1610
- Winning blow: queen to e6 (d7·4) — Chess960 specifics · 1650
- Chess960 tactic on a7 (d4) — Chess960 specifics · 2400
This position appears in course day 8
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Commentary
The king already stands on c1, so long castling moves the rook alone from b1. Both corners hold a bishop, a1 towards h8 and h1 towards a8, each with a single diagonal. On the second rank, a2 has no defender, and c2 leans on the king alone. The queen is on e1, the knights on d1 and f1, the second rook on g1. The search ran to depth 47 and calls it +28 centipawns: g3 e5 f4 g6 b4 exf4.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.