Starting position #543
Back-rank setup: RNKQNRBB
SP-543 · BastionGuard — King shifted to c or f, knights kept clear of the edges — 168 positions in all.
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 f1, the queen on d1.
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 512.
The engine's main line opens with e4, 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 83 Morozov Balance Index: 83 of 100 — class A — most balanced.
- Engine evaluation of the starting position: +16 centipawns for White (depth 43, 400 000 000 nodes).
- Rank 157 of 960 by balance — 1 is the most balanced start.
- Balance band S — slight edge · dynamics along the play-out: stable
- Evaluation along the engine's main line (60 half-moves): +28 → +23 → +28 → +14
Position facts
- Mirror twin: position #512
- The king starts on c, the rooks on a and f
- This position does not come up as the daily position in the next four years
Puzzles from this position
- Attack on the uncastled king: rook to d4 (f4) — Chess960 specifics · 780
- Winning blow: queen to e1 — Chess960 specifics · 780
- Attack on the uncastled king: rook to d5 (d1·2) — Chess960 specifics · 920
- Attack on the uncastled king: king to b1 (c1·5) — Chess960 specifics · 970
- Winning blow: knight to c5 (d3·9) — Chess960 specifics · 1060
- Attack on the uncastled king: rook to h4 (f4) — Chess960 specifics · 1250
- Winning blow: queen to c6 (c3·5) — Chess960 specifics · 1280
- Attack on the uncastled king: rook to h8 (h6) — Chess960 specifics · 1630
- Winning blow: pawn to f7 (f6·16) — Chess960 specifics · 1870
- Mate in 3: queen to d7 (e8) — Chess960 specifics · 1990
This position appears in course day 184
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Commentary
Both castlings are half-moves here: the king already stands on c1 for the long one, and the rook already occupies f1 for the short. A bishop holds the corner on h1 with one diagonal to a8; the second bishop is on g1. On the second rank, b2 leans on the king alone; no other second-rank pawn starts short of a defender. The queen is on d1 beside her king, the knights on b1 and e1. The engine takes the centre with e4, and Black's rook recaptures on the sixth half-move: e4 g5 Nc3 f5 exf5 Rxf5.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.