Starting position #39
Back-rank setup: NNBQRKRB
SP-39 · BastionScout — Off-centre king plus a rim knight (a/h): 168 positions carry this shape.
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 e1 and g1, the queen on d1.
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.
The second rank carries 2 pawns with no defender at all: a2, h2.
The setup belongs to the BastionScout family; read right to left it becomes position 914.
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 45, 400 000 000 nodes).
- Rank 64 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): +18 → +10 → 0 → 0
- Deeper check (1 200 000 000 nodes, depth 52): +7 cp, -3 cp against the base run — verified
Position facts
- Mirror twin: position #914
- The king starts on f, the rooks on e and g
- King and rook are neighbours — castling from adjacent squares feels unusual
- It becomes the daily position in 308 days
Puzzles from this position
- Winning blow: king to g2 — Chess960 specifics · 780
- Attack on the uncastled king: rook to d8 (d1·3) — Chess960 specifics · 780
- Attack on the uncastled king: pawn to h3 (g2·24) — Chess960 specifics · 780
- Winning blow: pawn to c5 (b4·3) — Chess960 specifics · 780
- Attack on the uncastled king: knight to a5 (b3·17) — Chess960 specifics · 780
- Winning blow: queen to g8 (h7·4) — Chess960 specifics · 1060
- Winning blow: rook to h6 (d6) — Chess960 specifics · 1200
- Mate in 2: queen to f7 (e6·2) — Chess960 specifics · 1320
- Winning blow: rook to h5 (h1·4) — Chess960 specifics · 1560
- Chess960 tactic on c7 (c8·2) — Chess960 specifics · 2120
This position appears in course day 1
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Commentary
Short castling swaps the king on f1 with the rook on g1. A knight starts in the corner on a1 with only b3 to go to, and a bishop in the corner on h1 with only one diagonal, to a8. The queen is on d1, the second knight on b1, the second bishop on c1. Three squares on the second rank are unusually exposed: a2 and h2 begin with no defender at all, while f2 has only the king. The line in the dataset opens d4 d5, then Nb3 Nb6 Nc3 O-O.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.