Starting position #115
Back-rank setup: BNQRNKRB
SP-115 · BastionGuard — The king starts one file off-centre, on c or f, with neither knight in a corner.
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 d1 and g1, the queen on c1.
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 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 BastionGuard family; read right to left it becomes position 835.
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 94 Morozov Balance Index: 94 of 100 — class A — most balanced.
- Engine evaluation of the starting position: +10 centipawns for White (depth 46, 400 000 000 nodes).
- Rank 62 of 960 by balance — 1 is the most balanced start.
- Balance band E — even · dynamics along the play-out: stable
- Evaluation along the engine's main line (51 half-moves): +29 → +9 → 0
- Deeper check (1 200 000 000 nodes, depth 51): +17 cp, +7 cp against the base run — verified · S — slight edge
Position facts
- Mirror twin: position #835
- The king starts on f, the rooks on d and g
- 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: knight to h7 (g5·2) — Chess960 specifics · 620
- Attack on the uncastled king: pawn to a6 (b5) — Chess960 specifics · 780
- Winning blow: rook to f6 — Chess960 specifics · 780
- Winning blow: bishop to d5 (h1·5) — Chess960 specifics · 920
- Winning blow: bishop to e4 (h1·2) — Chess960 specifics · 1200
- Winning blow: pawn to b8 (b7·12) — Chess960 specifics · 1610
- Mate in 3: rook to d8 (d1·3) — Chess960 specifics · 1630
- Mate in 2: rook to e8 (d8·5) — Chess960 specifics · 1670
- Winning blow: queen to e6 (g4·7) — Chess960 specifics · 1870
- Chess960 tactic on e6 (e4) — Chess960 specifics · 2250
This position appears in course day 2
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Commentary
Both corners hold a bishop, a1 towards h8 and h1 towards a8, each with a single diagonal. Short castling swaps the king on f1 with the rook on g1; long castling moves the king alone, since the rook is already on d1. Four second-rank squares are exposed: a2 and h2 have no defender at all, e2 and f2 only the king. The queen stands on c1, the knights on b1 and e1. The published line opens d4 d5, then g3 g6 b4 b6.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.