White 335 vs Black 959
White starts from setup 335 (NRQKRNBB), Black from setup 959 (RKRNNQBB). 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 #335 N R Q K R N B B
King on the d-file, rooks on b, e, 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 335 gives White +0.37 (Morozov Balance Index, 400M nodes).
Black: setup #959 R K R N N Q B B
King on the b-file, rooks on a, c, queen on the f-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 959 gives White +0.21 (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 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 -43 and +18 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.
For comparison, in symmetric play setup 335 gives White +0.37 and setup 959 gives White +0.21: 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 f4; the alternatives are slightly weaker but keep the game level.
Along the engine's main line (30 moves) the largest swing was 37 cp (around move 4), ending at 0 cp — the position stays playable for both sides.
Engine self-play agrees: 10 games, White won 2, drawn 7, Black won 1 (White scored 55.0%).
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 | 14 | -43 | 1. c4 g5 2. g4 f5 3. gxf5 Qxf5 4. d3 Qg6 |
| S1 | 500 000 | 17 | +2 | 1. c4 g5 2. g4 f5 3. gxf5 a5 4. Ng3 e6 |
| S2 | 2 000 000 | 25 | +13 | 1. f4 f5 2. c4 a5 3. g3 g6 4. d3 d6 |
| S3 | 8 000 000 | 27 | +18 | 1. f4 f5 2. c4 d5 3. Nb3 c6 4. Nc5 Rc7 |
| S4 | 32 000 000 | 31 | +11 | 1. f4 f5 2. c4 d5 3. Nb3 Nd6 4. Ne3 dxc4 |
| S5 | 128 000 000 | 39 | 0 | 1. f4 f5 2. c4 d5 3. Nb3 Nd6 4. Nc5 Qe8 |
| S6 | 400 000 000 | 47 | 0 | 1. f4 f5 2. c4 d5 3. Nb3 Nd6 4. Nc5 Qe8 |
| S7 | 800 000 000 | 54 | 0 | 1. f4 f5 2. c4 d5 3. Nb3 Nd6 4. Nc5 Qe8 |
| S8 | 1 600 000 000 | 55 | 0 | 1. f4 f5 2. c4 d5 3. Nb3 Nd6 4. Nc5 Qe8 |
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: +2
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 0, Black +76, difference -76. A balanced pair needs White's setup to be weaker by about the price of the first move.
Extended self-play: 10 games, 2 White wins, 7 draws, 1 Black wins, White scored 55.0%.
Best first moves
The 3 best first moves for White, searched together at 400 000 000 nodes.
| # | Eval, cp | Depth | Main line |
|---|---|---|---|
| 1 | +6 | 39 | 1. f4 f5 2. c4 d5 3. Nb3 Nd6 4. Nc5 Qe8 5. g4 g6 |
| 2 | -8 | 38 | 1. c4 g5 2. Nb3 c6 3. d3 f5 4. f4 gxf4 5. Qxf4+ e5 |
| 3 | -33 | 38 | 1. Nb3 f5 2. f4 a5 3. c4 g6 4. d3 Nf6 5. g3 d6 |
Main-line play-out
30 moves, 5 000 000 nodes per half-move. Largest |evaluation| 37 cp, mean 13.4 cp, final 0 cp.
| # | White | cp | Black | cp |
|---|---|---|---|---|
| 1 | f4 | +18 | f5 | +21 |
| 2 | c4 | +36 | d5 | +7 |
| 3 | Nb3 | -18 | Nd6 | -13 |
| 4 | Nc5 | -23 | Qe8 | -37 |
| 5 | g3 | -25 | c6 | -8 |
| 6 | b3 | -21 | g5 | -23 |
| 7 | d3 | +1 | gxf4 | 0 |
| 8 | gxf4 | +35 | b6 | +23 |
| 9 | Na6+ | +30 | Kb7 | +33 |
| 10 | Nb4 | +33 | a5 | +31 |
| 11 | Nc2 | +36 | c5 | +22 |
| 12 | Nfe3 | +21 | e6 | +22 |
| 13 | cxd5 | +20 | exd5 | +24 |
| 14 | Nxd5 | +17 | Ka7 | +14 |
| 15 | Qe3 | +22 | Qc6 | 0 |
| 16 | Qe7+ | 0 | N8b7 | 0 |
| 17 | Nce3 | +12 | Nb5 | +20 |
| 18 | a4 | +31 | Na3 | +25 |
| 19 | O-O-O | +20 | Bd4 | +20 |
| 20 | Bf3 | +24 | Re8 | +18 |
| 21 | Qc7 | +3 | Bxe3+ | 0 |
| 22 | Kb2 | 0 | Bxd5 | 0 |
| 23 | Qxc6 | 0 | Bxc6 | 0 |
| 24 | Bxc6 | 0 | Bxg1 | 0 |
| 25 | Rxg1 | 0 | Rxe2+ | 0 |
| 26 | Kxa3 | 0 | Rc8 | 0 |
| 27 | Bb5 | 0 | Rc7 | 0 |
| 28 | Rg8 | 0 | Nd6 | 0 |
| 29 | Rdg1 | 0 | Nxb5+ | 0 |
| 30 | axb5 | 0 | Rf7 | 0 |
Engine self-play
10 games at 500 000 nodes per move: White won 2, drawn 7, Black won 1 — White scored 55.0%. Average length 46.9 moves.
Sample game 1 (1-0)
1. c4 f5 2. f4 a5 3. g3 g6 4. d3 d6 5. Ne3 e5 6. fxe5 dxe5 7. Bf2 Nf6 8. b4 f4 9. Nec2 a4 10. b5 e4 11. gxf4 Ne6 12. Nb4 Re8 13. b6 cxb6 14. Nac2 Ng4 15. Bxb6 Nc5 16. Nc6+ Kc8 17. Qa3 Nf2+ 18. Kd2 e3+ 19. Kc1 Ncxd3+ 20. exd3 Qxa3+ 21. Nxa3 Nxd3+ 22. Kd1 Nf2+ 23. Ke2 Nxh1 24. Na7+ Rxa7 25. Bxa7 Nf2 26. Kf3 Ne4 27. Bxe3 Bc3 28. Red1 Bf7 29. Nb5 g5 30. Kg2 h6 31. f5 Bg8 32. Rbc1 Ba5 33. Rd4 Kb8 34. Rd7 Nf6 35. Ba7+ Ka8 36. Rd6 Ne4 37. Rxh6 Nc3 38. Bb6 Bxb6 39. Rxc3 Bd8 40. Nd6 Rf8 41. Ra3 Kb8 42. Rxa4 Be7 43. Rb4 Ka8 44. Kg3 Bf7 45. Kg4 Bg8 46. Rg6 Bf6 47. Ra4+ Kb8 48. Rb4 Ka8 49. Rxb7 Bxc4 50. Rxf6 Rxf6 51. Rd7 Rh6 52. Nxc4 Rxh2 53. Rd2 Rh4+ 54. Kxg5 Rh8 55. Ne5 Rg8+ 56. Ng6 Rb8 57. Rd5 Rb7 58. f6 Ka7 59. Ne5 Ka6 60. f7 Rb8
Sample game 2 (1/2-1/2)
1. f4 g6 2. d3 a5 3. g3 f5 4. c4 d6 5. Nc2 e5 6. fxe5 dxe5 7. Nfe3 Nf6 8. b4 axb4 9. Bf2 f4 10. gxf4 exf4 11. Nxb4 Nd7 12. O-O fxe3 13. Qxe3 Qd6 14. c5 Qxc5 15. Qxc5 Nxc5 16. Bxc5 Bxa2 17. Nxa2 Rxa2 18. Bf3 h5 19. Kh1 b6 20. Rg1 Rb2 21. Ra1 Nb7 22. Bf2 Rf8 23. Raf1 Rf6 24. d4 Rb5 25. Rc1 Nd6 26. Bh4 Re6 27. d5 Re8 28. Rxg6 Bd4 29. Re6 Rh8 30. Bg3 Bc5 31. Be5 Rh7 32. e4 h4 33. h3 Rf7 34. Bg2 Rf8 35. Re7 Rg8 36. Rg7 Rxg7 37. Bxg7 Rb3 38. Bf6 Nxe4 39. Bxe4 Rxh3+ 40. Kg2 Rg3+ 41. Kh1 Rh3+ 42. Kg2 Rg3+ 43. Kh2 Bd6 44. Kh1 Rh3+ 45. Kg1
Play it in the CH960 app
Open this page on a phone with the CH960 app installed, or find pair 335 / 959 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): rkrnnqbb/pppppppp/8/8/8/8/PPPPPPPP/NRQKRNBB w BEac - 0 1
Mirror twin (the same position mirrored): White 336 vs Black 0.
Current place in the live balance rating: 212.