Starting position #399
Back-rank setup: QRNNKRBB
SP-399 · ThroneGuard — Both knights start on inner files (b–g) while the king sits centrally on d or e — one of 204 positions filed here.
Move the pieces right on the board — full Chess960 rules, castle by dropping the king on the rook.
Position features
The king starts on e1, the rooks on b1 and f1, the queen on a1.
The kingside rook already stands on f1, so castling short moves only the king, from e1 to g1.
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: c2.
The setup belongs to the ThroneGuard family; read right to left it becomes position 752.
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 3 Morozov Balance Index: 3 of 100 — class D — largest edge.
- Engine evaluation of the starting position: +65 centipawns for White (depth 44, 400 000 000 nodes).
- Rank 932 of 960 by balance — 1 is the most balanced start.
- In 50 self-play games White scored 52.0% (95% CI 38.5–65.2%).
- Balance band L — large edge · dynamics along the play-out: volatile
- Evaluation along the engine's main line (60 half-moves): +63 → +77 → +54 → +14
Position facts
- Mirror twin: position #752
- The king starts on e, the rooks on b and f
- 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 h8 (a1·3) — Chess960 specifics · 780
- Attack on the uncastled king: knight to a2 (c1·4) — Chess960 specifics · 780
- Winning blow: pawn to a5 (b4·2) — Chess960 specifics · 920
- Attack on the uncastled king: queen to g8 (g6·2) — Chess960 specifics · 1060
- Attack on the uncastled king: pawn to g4 (g2) — Chess960 specifics · 1110
- Attack on the uncastled king: pawn to f4 (f3·3) — Chess960 specifics · 1250
- Winning blow: knight to e6 (c5·19) — Chess960 specifics · 1390
- Attack on the uncastled king: queen to f7 (a2·5) — Chess960 specifics · 1510
- Mate in 3: rook to h7 (h5) — Chess960 specifics · 1630
- Chess960 tactic on g8 (d8) — Chess960 specifics · 2350
This position appears in course day 85
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Commentary
White's edge here is unusually wide: +65 centipawns at depth 44. The rook already occupies f1, so short castling moves the king alone from e1. A bishop holds the corner on h1 with one diagonal to a8; the second bishop is on g1. On the second rank, c2 has no defender, and d2 leans on the king alone. The queen starts in the far corner on a1, the knights on c1 and d1, and the line runs b4 b6 f4 f6 d3 g6.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.