White 498 vs Black 144

The two setups

White: setup #498 B R Q N K B N R

King on the e-file, rooks on b, h, queen on the c-file; one bishop starts in a corner; the knights start on central files. Castling follows the Chess960 rule: king and rook end on the classical squares. In ordinary symmetric play setup 498 gives White +0.13 (Morozov Balance Index, 400M nodes).

Black: setup #144 B B N R N Q K R

King on the g-file, rooks on d, h, queen on the f-file; one bishop starts in a corner; the knights start on central files. The king already stands on a castled square, so one of the castlings moves only the rook. In ordinary symmetric play setup 144 gives White +0.25 (Morozov Balance Index, 400M nodes).

Why the pair is balanced

At the deepest rungs (400M, 800M, 1.6B, 3.2B nodes) the evaluation is exactly 0.00 each time, reaching search depth 64.

Admission rule: |cp| ≤ 5 at four budgets up to 4 billion nodes, no one-sided drift along the ladder, and confirmation by two independent engines — Berserk and Lc0 — each below its own median on symmetric positions. The same corridor is required at every deeper budget (8 G, 16 G) at which the pair has been evaluated.

The shallow rungs agreed early: from 100 thousand to 128 million nodes the evaluation never left ±12 cp.

For comparison, in symmetric play setup 498 gives White +0.13 and setup 144 gives White +0.25: with both sides on the same rank the first move is worth something. In this pair Black's own setup absorbs that edge completely.

The engine's first choice for White is b4; the alternatives are slightly weaker but keep the game level.

Along the engine's main line (19 moves) the evaluation stayed within ±16 cp the whole way: the balance holds as the pieces come out, not only on move one.

Engine self-play agrees: 10 games, White won 0, drawn 10, Black won 0 (White scored 50.0%).

Verification ladder

Nine independent searches of the starting position, each with a larger node budget. Evaluation in centipawns from White's point of view.

Deep verification

The search ladder reaches 1.6 billion nodes; admission needs a 4-billion rung and two further engines on top of that. Beyond even that, every pair was re-checked at budgets up to ten times larger and in thousands of self-play games. This section shows what each check returned for this pair.

This pair stays within the ±5 cp corridor up to 16 000 000 000 nodes.

Swap the two setups, giving White the black back rank and Black the white one, and the evaluation jumps to +55. The same two armies dealt the other way round are no longer balanced at all: that is how precisely this pair pays for the first move.

Independent engines, run on the same position:

• Berserk 14: 0
• Lc0 0.32.1: +10

Independent confirmations: 3 of 3. An engine counts as confirming when its reading of the pair is closer to equality than its own reading of a typical symmetric Chess960 position (+10 for Berserk, +18 for Lc0). Where only one engine confirms, the pair is balanced according to that engine alone, and this page says so.

Own weight of each setup, measured against the classical array: White +66, Black +113, difference -47. A balanced pair needs White's setup to be weaker by about the price of the first move.

Extended self-play: 160 games, 5 White wins, 155 draws, 0 Black wins, White scored 51.6%.

Best first moves

The 3 best first moves for White, searched together at 400 000 000 nodes.

Main-line play-out

19 moves, 5 000 000 nodes per half-move. Largest |evaluation| 16 cp, mean 4.3 cp, final 0 cp.

Engine self-play

10 games at 500 000 nodes per move: White won 0, drawn 10, Black won 0 — White scored 50.0%. Average length 31.2 moves.

1. Nf3 e6 2. g3 b6 3. b4 c5 4. bxc5 Qxc5 5. Bg2 O-O 6. c4 Qh5 7. O-O f5 8. Nb2 f4 9. Nd3 fxg3 10. fxg3 Nf6 11. c5 Be4 12. Qa3 Ng4 13. Qc3 Nf6 14. Qa3 Ng4 15. Qc3 Nf6

1. b4 e6 2. g3 b6 3. Nf3 c5 4. bxc5 Qxc5 5. Bg2 O-O 6. c4 Qh5 7. a4 Ne7 8. O-O f5 9. a5 f4 10. axb6 axb6 11. Rxb6 Nf5 12. Ra6 Bb7 13. Rb6 Bxf3 14. Bxf3 Qh3 15. Bg2 Qh5 16. Bf3 Qh3 17. Bg2 Qh5

Play it in the CH960 app

Open this page on a phone with the CH960 app installed, or find pair 498 / 144 in the app's encyclopedia, then choose how to play.

• Local game — two players on one device, with a clock.
• With a mentor — a clearly labelled training bot with hints, at your level.
• Challenge a friend — an online game by link; both players get the same pair, colours swap on rematch.

Play this pair against the computer, right here Play a friend

FEN (Shredder, castling rights by rook files): bbnrnqkr/pppppppp/8/8/8/8/PPPPPPPP/BRQNKBNR w BHdh - 0 1

Mirror twin: White 551 vs Black 815 — a different position (castling squares are fixed), not evaluated by the search.

Current place in the live balance rating: 69.