White 230 vs Black 306
White starts from setup 230 (NRBQKBNR), Black from setup 306 (BNQRKBRN). 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 #306 B N Q R K B R N
King on the e-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 306 gives White +0.33 (Morozov Balance Index, 400M nodes).
Why the pair is balanced
At the deepest rungs (400M, 800M, 1.6B nodes) the evaluation is exactly 0.00 each time, reaching search depth 53.
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 agreed early: from 100 thousand to 128 million nodes the evaluation never left ±12 cp.
For comparison, in symmetric play setup 230 gives White +0.47 and setup 306 gives White +0.33: 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 2 first moves are within 10 cp of it.
Along the engine's main line (30 moves) the evaluation stayed within ±29 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.
| Stage | Nodes | Depth | Eval, cp | Main line |
|---|---|---|---|---|
| S0 | 100 000 | 13 | +12 | 1. d4 b6 2. Qd3 g6 3. e4 f5 4. exf5 c5 |
| S1 | 500 000 | 19 | -4 | 1. d4 b6 2. Qd3 g6 3. e4 Bg7 4. h4 d5 |
| S2 | 2 000 000 | 23 | 0 | 1. d4 b6 2. Qd3 Qa6 3. Qxa6 Nxa6 4. f3 g5 |
| S3 | 8 000 000 | 26 | +12 | 1. d4 d5 2. h4 b6 3. c3 Nd7 4. Nf3 c5 |
| S4 | 32 000 000 | 30 | -1 | 1. d4 d5 2. c3 b6 3. Nf3 f6 4. h4 Nf7 |
| S5 | 128 000 000 | 38 | -3 | 1. d4 e6 2. Qd3 Ng6 3. h4 c5 4. c3 h5 |
| S6 | 400 000 000 | 45 | 0 | 1. d4 e6 2. Qd3 Ng6 3. h4 c5 4. c3 b6 |
| S7 | 800 000 000 | 50 | 0 | 1. d4 d5 2. h4 b6 3. Nf3 c5 4. c3 Nd7 |
| S8 | 1 600 000 000 | 53 | 0 | 1. d4 d5 2. Nf3 b6 3. c3 c5 4. h4 Nd7 |
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: -5
- 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 +51, difference -61. 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, 10 draws, 0 Black wins, White scored 50.0%.
Best first moves
The 3 best first moves for White, searched together at 400 000 000 nodes.
| # | Eval, cp | Depth | Main line |
|---|---|---|---|
| 1 | -20 | 39 | 1. d4 b6 2. Qd3 Ng6 3. h4 e5 4. d5 Bd6 5. e4 c6 |
| 2 | -30 | 39 | 1. h4 e6 2. d4 Be7 3. e4 b6 4. Bd3 c5 5. c3 f5 |
| 3 | -34 | 39 | 1. Nf3 c5 2. d4 cxd4 3. Qxd4 b6 4. Bd2 e6 5. Qd3 Ng6 |
Main-line play-out
30 moves, 5 000 000 nodes per half-move. Largest |evaluation| 29 cp, mean 8.2 cp, final 0 cp.
| # | White | cp | Black | cp |
|---|---|---|---|---|
| 1 | d4 | +22 | d5 | +12 |
| 2 | c3 | -11 | e6 | -13 |
| 3 | Qc2 | -16 | h6 | -10 |
| 4 | Bf4 | -5 | Ng6 | -14 |
| 5 | Bg3 | -13 | Bd6 | -19 |
| 6 | e3 | -2 | O-O | +6 |
| 7 | Bxd6 | +11 | Rxd6 | +17 |
| 8 | f4 | +3 | Nd7 | 0 |
| 9 | Bd3 | 0 | Ne7 | 0 |
| 10 | Nb3 | +3 | b6 | 0 |
| 11 | Qe2 | 0 | c5 | 0 |
| 12 | Nd2 | -8 | c4 | -13 |
| 13 | Bc2 | -14 | b5 | -17 |
| 14 | g4 | -9 | Rb6 | 0 |
| 15 | h4 | 0 | b4 | -8 |
| 16 | cxb4 | -25 | c3 | -22 |
| 17 | bxc3 | -29 | Qxc3 | -21 |
| 18 | Qd3 | -14 | Rc8 | -14 |
| 19 | Qh7+ | -7 | Kf8 | -10 |
| 20 | Qh8+ | -3 | Ng8 | -11 |
| 21 | Bd1 | -10 | Rxb4 | -10 |
| 22 | Ne2 | -14 | Qa3 | -17 |
| 23 | Rxb4 | -8 | Qxb4 | -9 |
| 24 | f5 | -5 | exf5 | -4 |
| 25 | Ng3 | -8 | g6 | -6 |
| 26 | gxf5 | -1 | Rc3 | 0 |
| 27 | O-O | 0 | Rxe3 | 0 |
| 28 | Nf3 | 0 | Qd6 | 0 |
| 29 | Kg2 | 0 | Bc6 | 0 |
| 30 | Rf2 | 0 | Rc3 | 0 |
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 40.5 moves.
Sample game 1 (1/2-1/2)
1. d4 b6 2. h4 f5 3. b4 e6 4. Bg5 Be7 5. Bxe7 Kxe7 6. e3 Rge8 7. c4 d6 8. b5 Kf8 9. Nc2 c5 10. bxc6 Nxc6 11. Nh3 Na5 12. Rc1 Nf7 13. Nb4 Rd7 14. d5 Rc7 15. Be2 exd5 16. Nxd5 Bxd5 17. Qxd5 Rc5 18. Qd3 d5 19. O-O dxc4 20. Qa3 Qe6 21. Nf4 Qe7 22. Rfd1 Ne5 23. h5 Nac6 24. h6 g5 25. Nh5 Rd8 26. Rxd8+ Nxd8 27. Qb2 Ndf7 28. Rxc4 Nxc4 29. Qg7+ Ke8 30. Nf6+ Kd8 31. Bxc4 Nxh6 32. Qh8+ Kc7 33. Nd5+ Rxd5 34. Bxd5 Ng4 35. g3 Ne5 36. Qa8 a5 37. f4 gxf4 38. gxf4 Ng4 39. Qc6+ Kd8 40. Qa8+ Kd7
Sample game 2 (1/2-1/2)
1. d4 b6 2. Nf3 e6 3. Qd3 Bb4+ 4. c3 f5 5. cxb4 Be4 6. Qa3 Bxb1 7. Bg5 Qa6 8. Qxa6 Nxa6 9. b5 Nb4 10. a3 Nc2+ 11. Nxc2 Bxc2 12. Bxd8 Kxd8 13. Ne5 Be4 14. e3 g5 15. f3 Bb7 16. Kf2 d6 17. Nd3 Ng6 18. Nb4 Kd7 19. Bc4 Ne7 20. a4 h5 21. h4 g4 22. Nd3 Ng6 23. fxg4 fxg4 24. Kg3 Ne7 25. Nf4 Nf5+ 26. Kf2 Ng7 27. Bd3 Rf8 28. Kg3 Nf5+ 29. Bxf5 Rxf5 30. Ne2 Be4 31. Nc3 Bc2 32. e4 Rf7 33. Rc1 Bb3 34. e5 dxe5 35. dxe5 Rf5 36. Re1 Bd5 37. b4 Ke7 38. Nd1 Kd7 39. Re3 Bc4 40. Re4 Bb3
Play it in the CH960 app
Open this page on a phone with the CH960 app installed, or find pair 230 / 306 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): bnqrkbrn/pppppppp/8/8/8/8/PPPPPPPP/NRBQKBNR w BHdg - 0 1
Mirror twin (the same position mirrored): White 630 vs Black 359.