Starting position #819
Back-rank setup: BRKNQRNB
SP-819 · 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 b1 and f1, the queen on e1.
The king already stands on c1, so castling long moves only the rook, from b1 to d1.
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 131.
The engine's main line opens with b3.
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 47, 400 000 000 nodes).
- Rank 149 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): +34 → +9 → +10 → 0
Position facts
- Mirror twin: position #131
- The king starts on c, the rooks on b and f
- King and rook are neighbours — castling from adjacent squares feels unusual
- It becomes the daily position in 464 days
Puzzles from this position
- Attack on the uncastled king: queen to e8 (e7) — Chess960 specifics · 620
- Attack on the uncastled king: bishop to e4 (h1·3) — Chess960 specifics · 780
- Attack on the uncastled king: bishop to d4 (a1·7) — Chess960 specifics · 780
- Winning blow: knight to f6 (d5·2) — Chess960 specifics · 920
- Winning blow: queen to f8 (g7·3) — Chess960 specifics · 1060
- Winning blow: queen to g7 (c3) — Chess960 specifics · 1060
- Attack on the uncastled king: rook to g8 (g1·7) — Chess960 specifics · 1090
- Attack on the uncastled king: rook to g8 (g6) — Chess960 specifics · 1090
- Mate in 2: knight to f6 (h7) — Chess960 specifics · 1220
- Chess960 tactic on c6 (a6) — Chess960 specifics · 2350
This position appears in course day 9
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Commentary
Both bishops start in the corners, on a1 and h1, each with a single long diagonal — one to h8, the other to a8. The king already stands on c1, so long castling moves the rook alone, and the rook already occupies f1, which leaves short castling to the king alone. Two pawns begin without a defender, a2 and h2, and the pawn on c2 leans on the king alone. The queen is on e1, the knights on d1 and g1, the second rook on b1. White's edge is a narrow +16 centipawns, and the line is a study in symmetry: b3 b6 e4 e5 g4 g5.
Written from the measured facts above and checked against the board before publishing. All 960 positions have one.