Starting position #671
Back-rank setup: RNKRNQBB
SP-671 · 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 c1, the rooks on a1 and d1, the queen on f1.
The king already stands on c1, so castling long moves only the rook, from a1 to d1.
A bishop starts in the corner on h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
The pawn on b2 is defended by the king alone — the same soft spot f2 is in the classical setup.
The setup belongs to the BastionGuard family; read right to left it becomes position 192.
The engine's main line opens with g4.
Every sentence here is computed from the setup itself and can be checked on the board.
Balance
MBI 69 Morozov Balance Index: 69 of 100 — class B — balanced.
- Engine evaluation of the starting position: +21 centipawns for White (depth 49, 400 000 000 nodes).
- Rank 292 of 960 by balance — 1 is the most balanced start.
- Balance band S — slight edge · dynamics along the play-out: equalizing
- Evaluation along the engine's main line (60 half-moves): +11 → -13 → -18 → 0
Position facts
- Mirror twin: position #192
- The king starts on c, the rooks on a and d
- King and rook are neighbours — castling from adjacent squares feels unusual
- It becomes the daily position in 804 days
Puzzles from this position
- Winning blow: bishop to e2 (g4) — Chess960 specifics · 920
- Winning blow: knight to c5 (d3·6) — Chess960 specifics · 920
- Attack on the uncastled king: king to b2 (a2) — Chess960 specifics · 970
- Winning blow: rook to e8 (h8·2) — Chess960 specifics · 1200
- Attack on the uncastled king: king to b1 (c1·12) — Chess960 specifics · 1250
- Attack on the uncastled king: queen to d7 (h3·4) — Chess960 specifics · 1320
- Mate in 2: queen to b8 (e8·2) — Chess960 specifics · 1320
- Castling-960 to the rescue on a1 (c1·7) — Castling-960 · 1340
- Winning blow: queen to g3 (h3·5) — Chess960 specifics · 1470
- Winning blow: bishop to e5 (f4·10) — Chess960 specifics · 1870
This position appears in course day 294
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Commentary
The king already stands on c1, so long castling moves the rook alone from d1. A bishop holds the corner on h1 with one diagonal to a8; the second bishop is on g1. Among the pawns, b2 leans on the king alone; no other second-rank pawn starts short of a defender. The queen is on f1, the knights on b1 and e1, the second rook in the corner on a1. The engine opens on the kingside and the g-file comes open for both: g4 g6 f4 f5 gxf5 gxf5.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.