White 230 vs Black 43
White starts from setup 230 (NRBQKBNR), Black from setup 43 (NNQRBKRB). In the encyclopedia since 2026-10-03: neither side starts better.
|cp| ≤ 5 at 400M · 800M · 1.6B · 4B nodes, two independent engines agree
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 #43 N N Q R B K R B
King on the f-file, rooks on d, g, queen on the c-file; one 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 43 gives White +0.15 (Morozov Balance Index, 400M nodes).
Why the pair is balanced
At the deepest rungs (400M, 800M, 1.6B nodes) the evaluation never left ±2 centipawns of equality, reaching search depth 55.
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 shallow rungs wandered between -22 and +8 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.
For comparison, in symmetric play setup 230 gives White +0.47 and setup 43 gives White +0.15: 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 d4, and 3 first moves are within 10 cp of it.
Along the engine's main line (30 moves) the evaluation stayed within ±22 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 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.
| Stage | Nodes | Depth | Eval, cp | Main line |
|---|---|---|---|---|
| S0 | 100 000 | 15 | -22 | 1. g3 d6 2. c3 c5 3. Bg2 O-O 4. d4 Bd7 |
| S1 | 500 000 | 22 | +4 | 1. c3 O-O 2. d4 d5 3. h4 c5 4. h5 Nc6 |
| S2 | 2 000 000 | 24 | +6 | 1. d4 O-O 2. Nb3 d6 3. e4 c5 4. Nf3 d5 |
| S3 | 8 000 000 | 25 | +3 | 1. d4 f5 2. c3 Nb6 3. a4 d6 4. a5 Nd5 |
| S4 | 32 000 000 | 34 | +8 | 1. d4 O-O 2. Nf3 Nb6 3. Nb3 d6 4. e4 c5 |
| S5 | 128 000 000 | 39 | -4 | 1. d4 d5 2. Nf3 c5 3. c3 O-O 4. h4 h5 |
| S6 | 400 000 000 | 46 | +2 | 1. d4 d5 2. Nb3 b6 3. h4 c5 4. Bf4 Nc7 |
| S7 | 800 000 000 | 52 | 0 | 1. d4 Nb6 2. Nf3 O-O 3. Nb3 d6 4. e4 c5 |
| S8 | 1 600 000 000 | 55 | 0 | 1. d4 Nb6 2. e4 d5 3. e5 c5 4. f4 f6 |
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.
| Nodes | Eval, cp |
|---|---|
| 4 000 000 000 | not checked |
| 8 000 000 000 | not checked |
| 16 000 000 000 | not checked |
This pair held exactly 0.00 up to 1 600 000 000 nodes.
Independent engines, run on the same position:
- Berserk 14: 0
- Lc0 0.32.1: -3
Independent confirmations: 2 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 +77, difference -87. A balanced pair needs White's setup to be weaker by about the price of the first move.
Extended self-play: 10 games, 0 White wins, 9 draws, 1 Black wins, White scored 45.0%.
Best first moves
The 3 best first moves for White, searched together at 400 000 000 nodes.
| # | Eval, cp | Depth | Main line |
|---|---|---|---|
| 1 | 0 | 41 | 1. d4 d5 2. Nb3 b6 3. h4 c5 4. Bf4 Nc7 5. Nf3 O-O |
| 2 | -8 | 40 | 1. h4 c5 2. c3 O-O 3. Nf3 d6 4. d3 Nc7 5. Nc2 h5 |
| 3 | -8 | 40 | 1. h4 Nb6 |
Main-line play-out
30 moves, 5 000 000 nodes per half-move. Largest |evaluation| 22 cp, mean 2.4 cp, final 0 cp.
| # | White | cp | Black | cp |
|---|---|---|---|---|
| 1 | d4 | +22 | f5 | -15 |
| 2 | c4 | +7 | c5 | +8 |
| 3 | d5 | +18 | d6 | +13 |
| 4 | g3 | +14 | b5 | +16 |
| 5 | cxb5 | +7 | Bxb5 | +4 |
| 6 | Nc2 | 0 | Nc7 | 0 |
| 7 | Bg2 | 0 | Qa6 | 0 |
| 8 | Nh3 | +5 | Nd7 | 0 |
| 9 | Na3 | 0 | Rb8 | 0 |
| 10 | Nf4 | 0 | g6 | 0 |
| 11 | O-O | 0 | O-O | 0 |
| 12 | Qc2 | 0 | Be5 | 0 |
| 13 | Ne6 | 0 | Rfc8 | 0 |
| 14 | Nxc7 | 0 | Rxc7 | 0 |
| 15 | Nxb5 | 0 | Qxb5 | 0 |
| 16 | b3 | 0 | c4 | -7 |
| 17 | e4 | -4 | Qb7 | -6 |
| 18 | exf5 | 0 | cxb3 | 0 |
| 19 | Qxb3 | 0 | Qa6 | 0 |
| 20 | Qa3 | 0 | Qxa3 | 0 |
| 21 | Rxb8+ | 0 | Nxb8 | 0 |
| 22 | Bxa3 | 0 | Rc2 | 0 |
| 23 | Bc1 | 0 | Rxa2 | 0 |
| 24 | Be3 | 0 | a5 | 0 |
| 25 | Rb1 | 0 | Na6 | 0 |
| 26 | fxg6 | 0 | hxg6 | 0 |
| 27 | Be4 | 0 | Kf7 | 0 |
| 28 | Rb6 | 0 | Nb4 | 0 |
| 29 | Rb7 | 0 | Ra1+ | 0 |
| 30 | Kg2 | 0 | Na6 | 0 |
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 42.8 moves.
Sample game 1 (1/2-1/2)
1. d4 Nb6 2. Nb3 f5 3. g4 d6 4. gxf5 Qxf5 5. Qd3 Bg6 6. Bg2 Qg4 7. Qg3 Qxg3 8. hxg3 Bxc2 9. Ra1 g5 10. Bxb7 c6 11. Be3 g4 12. f3 Nc4 13. Bf4 Ke8 14. fxg4 e5 15. dxe5 dxe5 16. Bh6 Nd6 17. Na5 Be4 18. Nf3 Rxg4 19. Rc1 Rxg3 20. Be3 Bf6 21. Bxa7 Rg7 22. Bxb8 Nxb7 23. Nxb7 Rxb7 24. Rh6 Bg7 25. Re6+ Kf8 26. Bxe5 Bd5 27. Bxg7+ Kxg7 28. Nd4 Rxb2 29. Re7+ Kf6 30. Rxh7 Rxa2 31. Nxc6 Bxc6 32. Rxc6+ Ke5 33. Rh5+ Kd4 34. Rh4+ Kd5 35. Rc3 Rf8 36. Rd3+ Ke5 37. Rb3 Ke6 38. Rh5 Kd7 39. Rhh3 Rfa8 40. Rbe3 Kd6
Sample game 2 (1/2-1/2)
1. d4 Nb6 2. e4 d5 3. e5 c5 4. Nb3 cxd4 5. Bd3 O-O 6. Nxd4 Nc6 7. Nxc6 Bxc6 8. f4 g6 9. Nf3 f6 10. O-O fxe5 11. Nxe5 Bb5 12. Nf3 Bf6 13. Bxb5 Qc5+ 14. Rf2 Qxb5 15. f5 gxf5 16. Nd4 Bxd4 17. Qxd4 Qc4 18. Qe5 Rf7 19. Bd2 Nd7 20. Qe3 Qc5 21. Qf4 Re8 22. Rf1 e6 23. h3 Qb6 24. c3 a6 25. g4 Rg7 26. Be3 Qd8 27. Rg2 fxg4 28. Rxg4 Qe7 29. Rf2 e5 30. Qf3 Qe6 31. Rxg7+ Kxg7 32. Rd2 Kh8 33. Kh2 Nf6 34. Rf2 Ne4 35. Rg2 b5 36. b3 Nf6 37. a4 Rg8 38. axb5 axb5 39. Rg5 Rg6 40. Qf1 b4 41. cxb4 d4 42. Rxg6 hxg6 43. Bg5 Kg7 44. b5 Nd7 45. Qc4 Qf5 46. h4 d3 47. Kg3 e4 48. b6 Ne5 49. Qc7+ Nf7
Play it in the CH960 app
Open this page on a phone with the CH960 app installed, or find pair 230 / 43 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): nnqrbkrb/pppppppp/8/8/8/8/PPPPPPPP/NRBQKBNR w BHdg - 0 1
Mirror twin (the same position mirrored): White 630 vs Black 913.