Starting position #407
Back-rank setup: RQBNNKRB
SP-407 · 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 f1, the rooks on a1 and g1, the queen on b1.
Castling short simply swaps the two pieces: the king on f1 and the rook on g1 trade places.
A bishop starts in the corner on h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
One second-rank pawn starts with no defender at all: h2.
The setup belongs to the BastionGuard family; read right to left it becomes position 738.
The engine's main line opens with d4, putting a pawn straight into the centre.
Every sentence here is computed from the setup itself and can be checked on the board.
Balance
MBI 83 Morozov Balance Index: 83 of 100 — class A — most balanced.
- Engine evaluation of the starting position: +16 centipawns for White (depth 45, 400 000 000 nodes).
- Rank 164 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 (60 half-moves): +22 → +6 → -3 → 0
Position facts
- Mirror twin: position #738
- The king starts on f, the rooks on a and g
- King and rook are neighbours — castling from adjacent squares feels unusual
- It becomes the daily position in 42 days
Puzzles from this position
- Attack on the uncastled king: pawn to d4 — Chess960 specifics · 780
- Attack on the uncastled king: bishop to g4 (f3) — Chess960 specifics · 780
- Winning blow: queen to g5 (c1) — Chess960 specifics · 780
- Winning blow: rook to f2 (f3) — Chess960 specifics · 970
- Winning blow: knight to e4 (c3·5) — Chess960 specifics · 1060
- Winning blow: rook to c7 (c1·15) — Chess960 specifics · 1200
- Attack on the uncastled king: queen to d6 (d3·4) — Chess960 specifics · 1420
- Winning blow: queen to g5 (g6) — Chess960 specifics · 1560
- Mate in 3: queen to h5 (h1) — Chess960 specifics · 1630
- Chess960 tactic on b6 (d6) — Chess960 specifics · 2120
This position appears in course day 21
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Commentary
Short castling swaps the king on f1 with the rook on g1. A bishop holds the corner on h1 with one diagonal to a8; the second bishop is on c1. Among the pawns, h2 has no defender, and e2 leans on the king alone. The queen is on b1, the knights on d1 and e1, the second rook in the corner on a1. The engine takes the centre with d4 and the line ends in a check: d4 g6 c3 d5 g3 Bh3+.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.