White 107 vs Black 811
White starts from setup 107 (QNRNBKRB), Black from setup 811 (RKQNBRNB). 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 #107 Q N R N B K R B
King on the f-file, rooks on c, g, queen on the a-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 107 gives White +0.31 (Morozov Balance Index, 400M nodes).
Black: setup #811 R K Q N B R N B
King on the b-file, rooks on a, f, queen on the c-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 811 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 56.
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 -2 and +31 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.
For comparison, in symmetric play setup 107 gives White +0.31 and setup 811 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.
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 67 cp (around move 17), ending at -9 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 | 18 | -2 | 1. b4 f5 2. c4 d6 3. d3 f4 4. Bc3 Nf6 |
| S1 | 500 000 | 18 | -2 | 1. b4 f5 2. c4 d6 3. d3 Nf6 4. Bc3 a5 |
| S2 | 2 000 000 | 23 | +31 | 1. b4 f5 2. c4 Nf6 3. d4 d6 4. Bc3 Ne4 |
| S3 | 8 000 000 | 30 | +2 | 1. b4 f5 2. c4 a5 3. b5 Nf6 4. g3 g5 |
| S4 | 32 000 000 | 31 | +15 | 1. b4 f5 2. c4 d6 3. d4 Ne6 4. g3 f4 |
| S5 | 128 000 000 | 45 | 0 | 1. b4 d6 2. c4 f5 3. d3 Nf6 4. Bc3 g5 |
| S6 | 400 000 000 | 51 | 0 | 1. b4 d6 2. c4 f5 3. Qb2 Nf6 4. d3 f4 |
| S7 | 800 000 000 | 54 | 0 | 1. b4 d6 2. c4 f5 3. d3 Nf6 4. Bc3 f4 |
| S8 | 1 600 000 000 | 56 | 0 | 1. b4 d6 2. c4 f5 3. d3 Nf6 4. Bc3 f4 |
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: +4
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 +26, Black +35, difference -9. 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 | 0 | 41 | 1. b4 d6 2. c4 f5 3. d3 Nf6 4. Bc3 f4 5. a4 g5 |
| 2 | -36 | 40 | 1. c4 a5 2. d3 g5 3. Bc3 Bxc3 4. Ndxc3 d6 5. b3 e5 |
| 3 | -37 | 40 | 1. d3 g5 2. c4 d6 3. Bc3 Bxc3 4. Ndxc3 a5 5. g3 Qh3+ |
Main-line play-out
30 moves, 5 000 000 nodes per half-move. Largest |evaluation| 67 cp, mean 31.4 cp, final -9 cp.
| # | White | cp | Black | cp |
|---|---|---|---|---|
| 1 | b4 | 0 | d6 | +9 |
| 2 | c4 | 0 | f5 | -8 |
| 3 | a4 | -12 | a5 | +2 |
| 4 | b5 | +1 | Nf6 | -3 |
| 5 | d3 | -6 | g5 | -40 |
| 6 | Bc3 | -40 | b6 | -37 |
| 7 | g3 | -45 | Nb7 | -39 |
| 8 | Ne3 | -41 | e5 | -35 |
| 9 | Nd2 | -50 | Qe6 | -58 |
| 10 | Nd5 | -45 | Bg6 | -41 |
| 11 | Nb3 | -48 | f4 | -53 |
| 12 | Nxf6 | -48 | Qxf6 | -45 |
| 13 | O-O | -48 | Qe7 | -40 |
| 14 | Bc6 | -47 | h5 | -49 |
| 15 | Kh1 | -43 | Be8 | -55 |
| 16 | gxf4 | -51 | gxf4 | -61 |
| 17 | Be4 | -55 | h4 | -67 |
| 18 | Rg1 | -58 | h3 | -51 |
| 19 | Qb1 | -51 | Bf6 | -38 |
| 20 | Bf3 | -40 | Qh7 | -33 |
| 21 | Be4 | -39 | Qe7 | -33 |
| 22 | Bf3 | -28 | Bf7 | -35 |
| 23 | d4 | -26 | e4 | -28 |
| 24 | Qxe4 | -16 | Qxe4 | -18 |
| 25 | Bxe4 | -19 | Bxc4 | -13 |
| 26 | Nd2 | -16 | Bxe2 | -16 |
| 27 | Rce1 | -11 | Bh5 | -8 |
| 28 | Bg6 | -16 | Bxg6 | -17 |
| 29 | Rxg6 | -14 | O-O-O | -17 |
| 30 | Rh6 | -10 | d5 | -9 |
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 44.6 moves.
Sample game 1 (1/2-1/2)
1. b4 d6 2. d4 Ne6 3. c4 f5 4. g3 f4 5. a4 Nf6 6. Bc3 Ng5 7. Bg2 Nh3 8. Rh1 g5 9. Ke1 g4 10. Nd2 Qf5 11. d5 Bg6 12. a5 a6 13. Bxh3 gxh3 14. Qb1 Qh5 15. Qb3 e5 16. dxe6 Re8 17. gxf4 Rxe6 18. Ne3 Ng4 19. Bxh8 Rxe3 20. Rc3 Re7 21. Rxh3 Qf5 22. Rg3 O-O-O 23. f3 Ne3 24. Ne4 Rxe4 25. fxe4 Qxe4 26. Qxe3 Qxh1+ 27. Rg1 Qc6 28. Qe6+ Kb8 29. Bc3 Re8 30. Qd5 Qd7 31. Rg3 Bf7 32. Qd3 Bg6 33. Qd5 Qe7 34. Qf3 Be4 35. Qh5 Bg6 36. Qf3 Be4 37. Qe3 Qf7 38. c5 Bc6 39. Qd2 Qh5 40. cxd6 Qxh2
Sample game 2 (1/2-1/2)
1. b4 f5 2. d3 f4 3. c4 Nf6 4. Bc3 g5 5. Nd2 d6 6. a4 a6 7. g3 Bc6 8. Bxc6 Nxc6 9. Rg2 e5 10. b5 Nd4 11. Bxd4 exd4 12. Qxd4 Re8 13. Qb2 g4 14. Qc2 axb5 15. axb5 Nh5 16. Rg1 Qf5 17. b6 cxb6 18. Ne4 Be5 19. d4 Bxd4 20. Nxd6 Qxc2 21. Rxc2 Rd8 22. Nf7 Rf8 23. Rd2 Bxf2 24. Nxf2 fxg3 25. hxg3 Rxf7 26. Rd8+ Ka7 27. Rxa8+ Kxa8 28. Kg2 Nf6 29. e4 Re7 30. Re1 Re5 31. Rf1 Ne8 32. Re1 Nd6 33. Nxg4 Rxe4 34. Rxe4 Nxe4 35. Kf3 Nxg3 36. Nf6 Nf1 37. Ke2 h6 38. Kxf1 Ka7 39. Ne4 Kb8 40. Ke2 Kc7 41. Kd3 h5 42. Kc3 h4 43. Ng5 Kc6 44. Kb4 b5 45. cxb5+ Kd5 46. Nf3 h3 47. Ka5 Kc5 48. Nh2 Kd4 49. Ng4
Play it in the CH960 app
Open this page on a phone with the CH960 app installed, or find pair 107 / 811 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): rkqnbrnb/pppppppp/8/8/8/8/PPPPPPPP/QNRNBKRB w CGaf - 0 1
Mirror twin (the same position mirrored): White 849 vs Black 145.