White 58 vs Black 593
White starts from setup 58 (NNRQBBKR), Black from setup 593 (BRQBNKRN). In the encyclopedia since 2026-10-15: neither side starts better.
|cp| ≤ 5 at 400M · 800M · 1.6B · 4B nodes, two independent engines agree
How to play with different setups
White sets up the pieces by position No. 58, Black by position No. 593, mirrored on their own side; the pawns stand as usual.
Moves as usual: White starts; everything else follows the Chess960 rules.
The two setups
White: setup #58 N N R Q B B K R
King on the g-file, rooks on c, h, queen on the d-file; no bishop starts in a corner; the knights start away from the centre. The king already stands on a castled square, so one of the castlings moves only the rook. In ordinary symmetric play setup 58 gives White +0.19 (Morozov Balance Index, 400M nodes).
Black: setup #593 B R Q B N K R N
King on the f-file, rooks on b, 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 593 gives White +0.02 (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 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 -38 and +15 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.
For comparison, in symmetric play setup 58 gives White +0.19 and setup 593 gives White +0.02: 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 c4, and 3 first moves are within 10 cp of it.
Along the engine's main line (30 moves) the evaluation stayed within ±18 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 | 16 | -38 | 1. c4 b6 2. d4 O-O 3. e3 c5 4. b4 f5 |
| S1 | 500 000 | 21 | -4 | 1. d4 b6 2. e3 O-O 3. c4 c5 4. Nc2 f5 |
| S2 | 2 000 000 | 26 | +12 | 1. d4 O-O 2. e3 b6 3. c4 c5 4. Nc2 e6 |
| S3 | 8 000 000 | 31 | +15 | 1. c4 b6 2. e3 O-O 3. Nc2 c5 4. f3 f5 |
| S4 | 32 000 000 | 38 | +4 | 1. c4 b6 2. e3 c5 3. Nc2 O-O 4. d4 e6 |
| S5 | 128 000 000 | 46 | 0 | 1. c4 b6 2. e3 O-O 3. Nc2 Qb7 4. d4 c5 |
| S6 | 400 000 000 | 52 | 0 | 1. c4 b6 2. e3 O-O 3. Nc3 c5 4. Nc2 Qb7 |
| S7 | 800 000 000 | 56 | 0 | 1. c4 b6 2. e3 O-O 3. Nc3 e6 4. Be2 f5 |
| S8 | 1 600 000 000 | 59 | 0 | 1. c4 b6 2. e3 O-O 3. Nc3 e6 4. Be2 f5 |
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 | 0 |
| 8 000 000 000 | not checked |
| 16 000 000 000 | not checked |
This pair stays within the ±5 cp corridor up to 4 000 000 000 nodes.
Independent engines, run on the same position:
- Berserk 14: 0
- Lc0 0.32.1: +12
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 +33, Black +137, difference -104. 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 | +11 | 44 | 1. c4 c5 2. Nc2 b6 3. e3 O-O 4. f3 e6 5. Nc3 Qb7 |
| 2 | +10 | 43 | 1. e3 c5 2. c4 O-O 3. Nc2 b6 4. d4 e6 5. Nc3 f5 |
| 3 | +10 | 43 | 1. e3 c5 |
Main-line play-out
30 moves, 5 000 000 nodes per half-move. Largest |evaluation| 18 cp, mean 4.1 cp, final 0 cp.
| # | White | cp | Black | cp |
|---|---|---|---|---|
| 1 | c4 | +12 | b6 | -1 |
| 2 | Nc2 | -8 | c5 | -5 |
| 3 | e3 | +15 | Qb7 | +12 |
| 4 | Nc3 | +4 | O-O | -3 |
| 5 | f3 | +3 | e6 | 0 |
| 6 | Be2 | 0 | Rc8 | 0 |
| 7 | d4 | 0 | f5 | 0 |
| 8 | O-O | +1 | Nf7 | +4 |
| 9 | b4 | 0 | cxd4 | 0 |
| 10 | Nxd4 | 0 | Nf6 | 0 |
| 11 | Bg3 | 0 | Nh5 | 0 |
| 12 | Bf2 | 0 | Bf6 | -3 |
| 13 | Na4 | -1 | Be5 | +9 |
| 14 | c5 | +17 | Nf6 | +18 |
| 15 | c6 | +15 | Qb8 | +2 |
| 16 | cxd7 | +6 | Rxc1 | +4 |
| 17 | Qxc1 | 0 | Bxd4 | 0 |
| 18 | exd4 | 0 | Qd8 | 0 |
| 19 | Nc3 | 0 | Qxd7 | 0 |
| 20 | Qd2 | +2 | Rc8 | 0 |
| 21 | Rc1 | 0 | h6 | 0 |
| 22 | Qe1 | 0 | Nd6 | +7 |
| 23 | a4 | +13 | Nd5 | +14 |
| 24 | b5 | +16 | g5 | +12 |
| 25 | Na2 | +17 | Kf7 | +13 |
| 26 | h4 | +7 | Rxc1 | 0 |
| 27 | Nxc1 | 0 | Qc8 | 0 |
| 28 | Nd3 | 0 | Qc3 | 0 |
| 29 | Ne5+ | 0 | Kf6 | 0 |
| 30 | Bd3 | 0 | Qxe1+ | 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 43.9 moves.
Sample game 1 (1/2-1/2)
1. h4 f5 2. c4 O-O 3. d4 b6 4. e3 c5 5. Nc2 Nf6 6. f3 e6 7. Nc3 a6 8. Rh3 Nf7 9. a4 Bb7 10. Bf2 d6 11. Ne1 e5 12. Nd3 Kh8 13. b3 Be7 14. Rh1 Qe8 15. Be2 Nh5 16. d5 Bc8 17. g4 e4 18. gxh5 exd3 19. Bxd3 Ne5 20. Bg3 Qxh5 21. Be2 Bd7 22. f4 Ng4 23. Bxg4 fxg4 24. Qd3 b5 25. cxb5 axb5 26. axb5 Rb7 27. e4 Rfb8 28. Kg2 Bxb5 29. Nxb5 Rxb5 30. Rc3 Bf6 31. e5 dxe5 32. fxe5 Bxe5 33. Bxe5 Qxe5 34. Rhc1 Qd6 35. Re1 Rb4 36. Re6 Qd7 37. Qf5 Rd4 38. Re5 Rd2+ 39. Kg3 Qd6 40. Qe6 Qf8 41. Rf5 Qd8 42. Re3 h6 43. h5 Ra8 44. Qe5 Rd1 45. Rf7 Qb8 46. Qxb8+ Rxb8 47. Rf5 Rb4 48. d6 Rxd6 49. Rxc5 Kh7 50. Rec3 Rd1 51. R5c4 Rb7 52. Rc7 Rb4 53. R7c4 Rb5 54. Rc5 Rxc5 55. Rxc5 Rd3+ 56. Kxg4 Rxb3 57. Rc8 Rb4+ 58. Kh3 Rb7 59. Kh4 Rb4+ 60. Kg3 Rb3+ 61. Kg4
Sample game 2 (1/2-1/2)
1. e3 b6 2. f3 e5 3. c4 c5 4. Nc3 O-O 5. Nc2 d6 6. d4 Bc6 7. Bg3 h5 8. h4 Ng6 9. dxe5 dxe5 10. e4 Nc7 11. Nd5 Ne6 12. Be1 Bd7 13. b3 Rb7 14. g3 Nd4 15. Nxd4 exd4 16. f4 Re8 17. Bd3 Bg4 18. Qc2 Ne7 19. Bd2 f5 20. e5 a5 21. Rh2 Qe6 22. Rf2 Kh7 23. Nxe7 Bxe7 24. Bf1 Qd7 25. a4 Rd8 26. Re1 Qe6 27. Ra1 Bf8 28. Qd3 Rbd7 29. Bg2 Kg6 30. Rff1 Be7 31. Rad1 Rc7 32. Bc1 Bxd1 33. Rxd1 Kh6 34. Kf2 Qg6 35. Bf3 Rf8 36. Bd2 Ra7 37. Bg2 Qe8 38. Bd5 Ra6 39. Re1 Qg6 40. Qf3 Ra7 41. Qd3 Bd8 42. Rg1 Qg4 43. Ke1 Rc7 44. Bf3 Qg6 45. Bd5
Play it in the CH960 app
Open this page on a phone with the CH960 app installed, or find pair 58 / 593 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): brqbnkrn/pppppppp/8/8/8/8/PPPPPPPP/NNRQBBKR w CHbg - 0 1
Mirror twin: White 901 vs Black 267 — a different position (castling squares are fixed), not evaluated by the search.
Current place in the live balance rating: 244.