White 230 vs Black 447

The two setups

White: setup #230 N R B Q K B N R

King on the e-file, rooks on b, h, queen on the d-file; no bishop starts in a corner; the knights start away from the centre. Castling follows the Chess960 rule: king and rook end on the classical squares. In ordinary symmetric play setup 230 gives White +0.47 (Morozov Balance Index, 400M nodes).

Black: setup #447 R N N Q K R B B

King on the e-file, rooks on a, f, 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 447 gives White +0.28 (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 65.

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 ±0 cp.

For comparison, in symmetric play setup 230 gives White +0.47 and setup 447 gives White +0.28: 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 e4, and 3 first moves are within 10 cp of it.

Along the engine's main line (30 moves) the largest swing was 37 cp (around move 2), ending at 0 cp — the position stays playable for both sides.

Engine self-play agrees: 10 games, White won 0, drawn 9, Black won 1 (White scored 45.0%).

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 +69. 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: -6

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 -10, Black +48, difference -58. A balanced pair needs White's setup to be weaker by about the price of the first move.

Extended self-play: 160 games, 0 White wins, 143 draws, 17 Black wins, White scored 44.7%.

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| 37 cp, mean 12.0 cp, final 0 cp.

Engine self-play

10 games at 500 000 nodes per move: White won 0, drawn 9, Black won 1 — White scored 45.0%. Average length 41.0 moves.

1. Nf3 f5 2. Nb3 g6 3. d3 Bg7 4. e4 fxe4 5. dxe4 Nc6 6. Bd3 a5 7. a3 a4 8. Nbd2 Ba2 9. Ra1 Be6 10. O-O Nb6 11. Rb1 Ba2 12. Ra1 Be6 13. h3 d6 14. Rb1 Ba2 15. Ra1 Be6 16. Re1 Qd7 17. Rb1 Ba2 18. Ra1 Be6 19. Rb1 Ba2 20. Ra1

1. Nb3 f5 2. g3 a5 3. d4 a4 4. Nd2 Bxa2 5. Ra1 Bd5 6. Ngf3 b5 7. Bg2 g6 8. e4 fxe4 9. Ng5 e6 10. Ndxe4 Qe7 11. c3 Nb6 12. O-O Nc6 13. Re1 O-O 14. h4 Na5 15. h5 Nb3 16. Rb1 Nxc1 17. hxg6 hxg6 18. Rxc1 Bf6 19. Nh3 Qf7 20. Nc5 Bxg2 21. Kxg2 Bg7 22. Ra1 Qf5 23. Ne4 Nd5 24. Ra3 Nb6 25. Ra1 Nd5 26. Ra3 c6 27. Ra1 e5 28. dxe5 Bxe5 29. c4 bxc4 30. Rxa4 Rxa4 31. Qxa4 Qf3+ 32. Kg1 Qg4 33. Kg2 Qf3+ 34. Kg1 Qd3 35. Nc5 Qf5 36. Qxc4 Bxg3 37. fxg3 Qxh3 38. Qd3 Qg4 39. Rf1 Rxf1+ 40. Kxf1 Kf7 41. b3 Ke7 42. Ne4 d6 43. Kg1 Qf5 44. Qe2 Qe5 45. Qd3 c5 46. Kg2 Nf6 47. Nf2 Qd5+ 48. Qxd5 Nxd5 49. Kf3 Ke6 50. Kg4 Kf6 51. Nd3 Nc3 52. Kf3 g5 53. Ke3 Kf5 54. Nf2 Nd5+ 55. Kf3 Nf6 56. Nd3 g4+ 57. Ke3 Ne4 58. Nf4 Nxg3 59. Nd3 Nh5 60. b4 cxb4 61. Nxb4 Nf4 62. Nc2 Nd5+ 63. Kf2 Kf4 64. Nd4 g3+ 65. Kf1 Kg4 66. Ke2 Nf4+ 67. Ke3 g2 68. Kf2 Kh3 69. Nf5 Kh2 70. Kf3 Ne6 71. Ke4 g1=Q 72. Kd5 Qc5+

Play it in the CH960 app

Open this page on a phone with the CH960 app installed, or find pair 230 / 447 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): rnnqkrbb/pppppppp/8/8/8/8/PPPPPPPP/NRBQKBNR w BHaf - 0 1

Mirror twin: White 630 vs Black 704 — a different position (castling squares are fixed), not evaluated by the search.

Current place in the live balance rating: 50.