Starting position #161
Back-rank setup: BNRBNKQR
SP-161 · BastionGuard — Off-centre king (c/f), no knight on the a- or h-file.
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 c1 and h1, the queen on g1.
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 BastionGuard family; read right to left it becomes position 795.
The engine's main line opens with f4.
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 44, 400 000 000 nodes).
- Rank 31 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): +20 → +19 → +15 → +5 → 0
- Deeper check (1 200 000 000 nodes, depth 49): +10 cp, +4 cp against the base run — verified
Position facts
- Mirror twin: position #795
- The king starts on f, the rooks on c and h
- It becomes the daily position in 968 days
Puzzles from this position
- Attack on the uncastled king: queen to b7 — Chess960 specifics · 780
- Attack on the uncastled king: knight to a3 (b5) — Chess960 specifics · 780
- Attack on the uncastled king: pawn to d5 (c4·68) — Chess960 specifics · 780
- Attack on the uncastled king: bishop to h5 (d1·19) — Chess960 specifics · 780
- Attack on the uncastled king: queen to d6 (h2) — Chess960 specifics · 780
- Winning blow: pawn to f3 (g2·11) — Chess960 specifics · 920
- Mate in 2: queen to g4 (c8) — Chess960 specifics · 1090
- Attack on the uncastled king: pawn to g5 (f4·40) — Chess960 specifics · 1200
- Winning blow: rook to g8 (g5·6) — Chess960 specifics · 1430
- Chess960 tactic on e5 (d4) — Chess960 specifics · 2250
This position appears in course day 11
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Commentary
Castling is ordinary in both directions from f1, with the queen on g1 beside the king. A bishop is shut into the corner on a1 and needs the b-pawn before its diagonal to h8 opens; the second is on d1. Among the pawns, a2 begins with no defender at all. The rooks are on c1 and h1, the knights on b1 and e1. The engine's line opens f4 b6, then e3 e6 Bf3 Bxf3 — the light-square bishops are traded on the sixth half-move.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.