White 179 vs Black 496

The two setups

White: setup #179 B N R N K R Q B

King on the e-file, rooks on c, f, queen on the g-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 179 gives White +0.18 (Morozov Balance Index, 400M nodes).

Black: setup #496 B B R Q N K N R

King on the f-file, rooks on c, h, queen on the d-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 496 gives White +0.20 (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 59.

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 wandered between -2 and +32 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.

For comparison, in symmetric play setup 179 gives White +0.18 and setup 496 gives White +0.20: with both sides on the same rank the first move is worth something. In this pair Black's own setup absorbs that edge completely.

White is not forced into a single path: the best first move is g3, and 2 first moves are within 10 cp of it.

Along the engine's main line (30 moves) the evaluation stayed within ±27 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: +1

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 +111, Black +88, difference +23. A balanced pair needs White's setup to be weaker by about the price of the first move.

Extended self-play: 160 games, 3 White wins, 156 draws, 1 Black wins, White scored 50.6%.

Best first moves

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

Main-line play-out

30 moves, 5 000 000 nodes per half-move. Largest |evaluation| 27 cp, mean 4.9 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 38.2 moves.

1. g4 c5 2. c4 e6 3. f4 Ne7 4. b3 d5 5. cxd5 Nxd5 6. f5 Qh4+ 7. Qf2 Qxh2 8. Qxh2 Bxh2 9. fxe6 Bg3+ 10. Nf2 fxe6 11. Nc3 Ndf6 12. g5 Ng4 13. Ne4 Bh4 14. O-O-O Nxf2 15. Nxf2 O-O 16. Nh3 Rxf1 17. Rxf1 Nd6 18. Rg1 Nf5 19. Bf3 Bg3 20. g6 h6 21. e4 Bh2 22. exf5 Bxg1 23. Nxg1 b5 24. Be2 c4 25. bxc4 Bd5 26. Kb1 Bxc4 27. d3 Bd5 28. Nh3 Rf8 29. Be5 Rxf5 30. d4 Bc4 31. Bxc4 bxc4 32. Nf4 h5 33. Nxe6 h4 34. Nf4 Kf8 35. Kc2 Ke8 36. Ne6 Ke7 37. Nf4 Kd7 38. Kd2 Ke7 39. Kc2 Ke8 40. Ne6 Kd7 41. Nf4

1. g4 d5 2. f4 c5 3. c4 e6 4. b3 Ne7 5. cxd5 Nxd5 6. f5 Qh4+ 7. Qf2 Qxh2 8. Qxh2 Bxh2 9. fxe6 Bg3+ 10. Nf2 fxe6 11. Nc3 b6 12. Nxd5 exd5 13. Rc3 Bxf2+ 14. Rxf2+ Kg8 15. d4 h5 16. Bf3 hxg4 17. Bxg4 Rc6 18. Rf1 Nf6 19. Bf3 cxd4 20. Rxc6 Bxc6 21. Bxd4 Kf7 22. Bb2 Ke6 23. Kd2 Bd7 24. Ba1 Be8 25. Rg1 Rh7 26. Rg5 Bd7 27. Ke3 Be8 28. Re5+ Kf7 29. Bxd5+ Nxd5+ 30. Rxd5 Rh6 31. Rg5 Re6+ 32. Be5 Rg6 33. Rxg6 Kxg6 34. Kd4 Kf7 35. Bb8 a6 36. Bc7 b5 37. Bd8 Ke6 38. e4 Kd7 39. Ba5 Kc6 40. Bc3 Bg6 41. Ba5 Bh5 42. Bc3 Bf7 43. Ke5 Bg6 44. Kf4 Bh7 45. Bxg7 a5 46. Bc3 a4 47. Bb4 Kd7 48. Ke5 axb3

Play it in the CH960 app

Open this page on a phone with the CH960 app installed, or find pair 179 / 496 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): bbrqnknr/pppppppp/8/8/8/8/PPPPPPPP/BNRNKRQB w CFch - 0 1

Mirror twin: White 771 vs Black 559 — a different position (castling squares are fixed), not evaluated by the search.

Current place in the live balance rating: 39.