Starting position #595
Back-rank setup: BRQNKRNB
SP-595 · ThroneGuard — A central king (d or e) and two knights tucked onto inner files: the family that holds the standard array, SP-518.
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 c1.
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 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 ThroneGuard family; read right to left it becomes position 259.
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 91 Morozov Balance Index: 91 of 100 — class A — most balanced.
- Engine evaluation of the starting position: +13 centipawns for White (depth 46, 400 000 000 nodes).
- Rank 89 of 960 by balance — 1 is the most balanced start.
- Balance band S — slight edge · dynamics along the play-out: stable
- Evaluation along the engine's main line (70 half-moves): +29 → +10 → 0 → 0
- Deeper check (1 200 000 000 nodes, depth 51): +18 cp, +5 cp against the base run — verified
Position facts
- Mirror twin: position #259
- The king starts on e, the rooks on b and f
- King and rook are neighbours — castling from adjacent squares feels unusual
- It becomes the daily position in 77 days
Puzzles from this position
- Winning blow: queen to e7 — Chess960 specifics · 780
- Attack on the uncastled king: bishop to h8 (a1·6) — Chess960 specifics · 780
- Attack on the uncastled king: pawn to d5 (c4·72) — Chess960 specifics · 780
- Winning blow: queen to g7 (a1) — Chess960 specifics · 970
- Attack on the uncastled king: knight to g4 (e3·10) — Chess960 specifics · 1060
- Winning blow: bishop to d6 (e5·5) — Chess960 specifics · 1110
- Attack on the uncastled king: queen to a7 (a3) — Chess960 specifics · 1200
- Winning blow: king to a1 (b1·17) — Chess960 specifics · 1250
- Mate in 3: knight to e6 (c7·4) — Chess960 specifics · 1630
- Attack on the uncastled king: rook to b8 (b6·2) — Chess960 specifics · 2060
This position appears in course day 54
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Commentary
The rook already occupies f1, so short castling moves the king alone from e1. Both corners hold a bishop, a1 towards h8 and h1 towards a8, each with a single diagonal. Two pawns begin with no defender at all: a2 and h2. The queen is on c1, the knights on d1 and g1, the second rook on b1. The engine keeps the edge small, +13 centipawns, and both sides castle: b4 b5 Nf3 Nf6 O-O O-O.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.