White 485 vs Black 2
White starts from setup 485 (QRBBNKNR), Black from setup 2 (BQNNRBKR). In the encyclopedia since 2026-10-21: neither side starts better.
|cp| ≤ 5 at 400M · 800M · 1.6B · 4B nodes, two independent engines agree
The two setups
White: setup #485 Q R B B N K N R
King on the f-file, rooks on b, h, queen on the a-file; no 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 485 gives White +0.03 (Morozov Balance Index, 400M nodes).
Black: setup #2 B Q N N R B K R
King on the g-file, rooks on e, h, queen on the b-file; one bishop starts in a corner; the knights start on central files. The king already stands on a castled square, so one of the castlings moves only the rook. In ordinary symmetric play setup 2 gives White +0.23 (Morozov Balance Index, 400M nodes).
Why the pair is balanced
At the deepest rungs (400M, 800M, 1.6B nodes) the evaluation never left ±3 centipawns of equality, reaching search depth 54.
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 -18 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 485 gives White +0.03 and setup 2 gives White +0.23: 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 b4; the alternatives are slightly weaker but keep the game level.
Along the engine's main line (30 moves) the largest swing was 44 cp (around move 9), ending at +11 cp — the position stays playable for both sides.
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 | 15 | -18 | 1. b4 e5 2. Nh3 b5 3. a4 bxa4 4. Qxa4 c5 |
| S1 | 500 000 | 20 | -2 | 1. b4 e5 2. c4 h5 3. h4 b6 4. d3 c5 |
| S2 | 2 000 000 | 23 | +14 | 1. b4 e5 2. c4 b6 3. e3 c5 4. bxc5 Bxc5 |
| S3 | 8 000 000 | 27 | +15 | 1. b4 e5 2. c4 b6 3. e3 h5 4. Ne2 h4 |
| S4 | 32 000 000 | 31 | +13 | 1. b4 e5 2. c4 h5 3. Ngf3 e4 4. Ng5 b5 |
| S5 | 128 000 000 | 41 | 0 | 1. b4 e5 2. c4 b6 3. h4 h5 4. d3 e4 |
| S6 | 400 000 000 | 47 | -3 | 1. b4 e5 2. c4 b6 3. e3 h5 4. Nh3 c5 |
| S7 | 800 000 000 | 52 | 0 | 1. b4 e5 2. c4 b6 3. d3 c5 4. bxc5 Bxc5 |
| S8 | 1 600 000 000 | 54 | 0 | 1. b4 e5 2. a4 d5 3. Ngf3 Bd6 4. d3 b6 |
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: -2
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 +48, Black +134, difference -86. 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 | +13 | 40 | 1. b4 e5 2. c4 b6 3. d3 c5 4. bxc5 Bxc5 5. Bb2 O-O |
| 2 | -17 | 40 | 1. c4 c5 2. a3 e5 3. b4 b6 4. bxc5 Bxc5 5. Bb2 Bf8 |
| 3 | -29 | 39 | 1. e3 c5 2. c4 e5 3. d3 b5 4. b3 e4 5. Ne2 h5 |
Main-line play-out
30 moves, 5 000 000 nodes per half-move. Largest |evaluation| 44 cp, mean 20.6 cp, final +11 cp.
| # | White | cp | Black | cp |
|---|---|---|---|---|
| 1 | b4 | +20 | e5 | +11 |
| 2 | c4 | +23 | h5 | +18 |
| 3 | d3 | +24 | b6 | +22 |
| 4 | Ngf3 | +30 | c5 | +32 |
| 5 | bxc5 | +33 | Bxc5 | +29 |
| 6 | Bb2 | +40 | f6 | +36 |
| 7 | O-O | +36 | h4 | +39 |
| 8 | h3 | +43 | e4 | +37 |
| 9 | dxe4 | +44 | Bxe4 | +33 |
| 10 | Nd3 | +29 | Ne6 | +34 |
| 11 | Ba4 | +36 | Qc7 | +33 |
| 12 | Rbd1 | +34 | Nd6 | +36 |
| 13 | Nxc5 | +27 | Nxc5 | +22 |
| 14 | Ba3 | +24 | Nxa4 | +24 |
| 15 | Rxd6 | +19 | Nc5 | +16 |
| 16 | Qd4 | +17 | Rh5 | +12 |
| 17 | Rd1 | +14 | Qb8 | +8 |
| 18 | Qb2 | +8 | Bc6 | +10 |
| 19 | R6d4 | +19 | Ne4 | +13 |
| 20 | Qb3 | +13 | Nc5 | +13 |
| 21 | Qb2 | +11 | Ne4 | +14 |
| 22 | Bd6 | +14 | Qb7 | +16 |
| 23 | Bf4 | +8 | Qa6 | +11 |
| 24 | Rc1 | +8 | Ra5 | +12 |
| 25 | Rc2 | +10 | Ba4 | +12 |
| 26 | Bd2 | +8 | Rh5 | +14 |
| 27 | Rc1 | +10 | Bc6 | +9 |
| 28 | Be3 | +15 | Ra5 | +9 |
| 29 | Rc2 | +12 | Ba4 | +12 |
| 30 | Rc1 | +12 | Bc6 | +11 |
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 40.9 moves.
Sample game 1 (1/2-1/2)
1. c4 c5 2. b4 cxb4 3. a3 bxa3 4. Bxa3 e5 5. Bxf8 Rxf8 6. Ngf3 Re8 7. O-O O-O 8. d4 exd4 9. Nxd4 Ne6 10. Nd3 Nd6 11. c5 Ne4 12. Nf5 Nd2 13. Bb3 f6 14. Qa4 b5 15. Bxe6+ dxe6 16. Rxb5 Qc7 17. Rd1 Ne4 18. Qc4 Bd5 19. Qd4 Rd8 20. Nd6 Nxd6 21. cxd6 Rxd6 22. Rc1 Qd7 23. Qb4 Rc6 24. Rxc6 Bxc6 25. Ra5 Ra8 26. f3 Qc7 27. Nf4 Kf7 28. Ra6 Bd7 29. Qe4 Qc5+ 30. Kf1 Rb8 31. Nxe6 Qe7 32. Nc7 Qxe4 33. fxe4 Rb7 34. Nd5 Bb5 35. Ra5 a6 36. Kf2 Ke6 37. g4 Kd6 38. h4 Kc5 39. Kf3 Kd6 40. Nb4 Ra7 41. Nd5 h6 42. Ke3 Kc6 43. Kf3 Ra8 44. Ke3 Kd6 45. Nc3 Kc5 46. Nd5 Rb8 47. Ne7 Rb7 48. Nd5 Kd6
Sample game 2 (1/2-1/2)
1. c4 e5 2. b4 c5 3. bxc5 Bxc5 4. e3 b6 5. Ne2 Bd6 6. a4 O-O 7. d3 f5 8. O-O Ne6 9. a5 e4 10. h3 f4 11. exf4 Nxf4 12. Nxf4 Bxf4 13. dxe4 Bxe4 14. Bc2 Bxc1 15. Bxe4 Rxe4 16. Rxc1 Qe5 17. Qxe5 Rxe5 18. axb6 Nxb6 19. Nd3 Re2 20. c5 Nd5 21. Ra1 Ra8 22. Ra4 Rd2 23. Ne5 Nf6 24. c6 Rd5 25. f4 dxc6 26. Nxc6 Rc5 27. Nd4 Nd5 28. Ne6 Rc6 29. Re1 Re8 30. f5 Nc7 31. Rxa7 Nxe6 32. fxe6 Rcxe6 33. Rxe6 Rxe6 34. g4 h5 35. gxh5 Re2 36. Ra8+ Kh7 37. Ra6 Rb2 38. Rc6 Ra2 39. Rb6 Ra5 40. Kh2 Rxh5
Play it in the CH960 app
Open this page on a phone with the CH960 app installed, or find pair 485 / 2 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): bqnnrbkr/pppppppp/8/8/8/8/PPPPPPPP/QRBBNKNR w BHeh - 0 1
Mirror twin: White 570 vs Black 951 — a different position (castling squares are fixed), not evaluated by the search.