Starting position #226
Back-rank setup: BNRQKBNR
SP-226 · ThroneGuard — A centre-file king with no knight on the edge; a position and its mirror twin always share this family.
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 c1 and h1, the queen on d1.
Castling ends where it always does: king to g1 and rook to f1 on the short side, king to c1 and rook to d1 on the long one.
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 ThroneGuard family; read right to left it becomes position 631.
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 97 Morozov Balance Index: 97 of 100 — class A — most balanced.
- Engine evaluation of the starting position: +6 centipawns for White (depth 50, 400 000 000 nodes).
- Rank 29 of 960 by balance — 1 is the most balanced start.
- Balance band E — even · dynamics along the play-out: equalizing
- Evaluation along the engine's main line (70 half-moves): +12 → -6 → 0 → -8 → -6
- Deeper check (1 200 000 000 nodes, depth 54): 0 cp, -6 cp against the base run — verified
Position facts
- Mirror twin: position #631
- The king starts on e, the rooks on c and h
- It becomes the daily position in 629 days
Puzzles from this position
- Attack on the uncastled king: king to f2 (e1·3) — Chess960 specifics · 780
- Attack on the uncastled king: king to f2 (e1·5) — Chess960 specifics · 780
- Attack on the uncastled king: queen to e7 (e2·3) — Chess960 specifics · 850
- Attack on the uncastled king: knight to d6 (c4·3) — Chess960 specifics · 920
- Winning blow: rook to d1 (c1) — Chess960 specifics · 1060
- Winning blow: knight to b7 (c5·4) — Chess960 specifics · 1200
- Mate in 2: queen to d6 (d1) — Chess960 specifics · 1320
- Attack on the uncastled king: rook to c8 (c5) — Chess960 specifics · 1510
- Mate in 3: rook to h7 (h1·2) — Chess960 specifics · 1760
- Mate in 3: queen to c6 (c3·4) — Chess960 specifics · 2170
This position appears in course day 47
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Commentary
The engine sees almost nothing in it for White here — the starting evaluation sits close to level. Castling is ordinary in both directions from e1, with the queen on d1 next to her king. Among the pawns, a2 has no defender at all, and f2 only the king. A bishop is shut into the corner on a1; the second is on f1. The main line opens b4 e6, then c4 Nf6 b5 c6.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.