White 9 vs Black 949
White starts from setup 9 (QNNBBRKR), Black from setup 949 (RKBBRNNQ). In the encyclopedia since 2026-10-10: neither side starts better.
|cp| ≤ 5 at 400M · 800M · 1.6B · 4B nodes, two independent engines agree
The two setups
White: setup #9 Q N N B B R K R
King on the g-file, rooks on f, h, queen on the a-file; no 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 9 gives White +0.22 (Morozov Balance Index, 400M nodes).
Black: setup #949 R K B B R N N Q
King on the b-file, rooks on a, e, queen on the h-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 949 gives White +0.30 (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 51.
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 agreed early: from 100 thousand to 128 million nodes the evaluation never left ±11 cp.
For comparison, in symmetric play setup 9 gives White +0.22 and setup 949 gives White +0.30: 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 largest swing was 54 cp (around move 14), ending at -20 cp — the position stays playable for both sides.
Engine self-play agrees: 10 games, White won 0, drawn 9, Black won 1 (White scored 45.0%).
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 | -10 | 1. d4 d6 2. c4 e5 3. dxe5 dxe5 4. Ba4 c6 |
| S1 | 500 000 | 19 | -3 | 1. c4 e5 2. b4 f5 3. Nb3 Nf6 4. Nc3 g5 |
| S2 | 2 000 000 | 23 | +11 | 1. d4 g5 2. b4 e5 3. dxe5 Ng6 4. Bc3 Nxe5 |
| S3 | 8 000 000 | 26 | 0 | 1. d4 a5 2. c4 d6 3. Ba4 Bd7 4. Nc3 g5 |
| S4 | 32 000 000 | 34 | +4 | 1. d4 g5 2. b4 f5 3. c4 Nf6 4. Nd3 h5 |
| S5 | 128 000 000 | 37 | 0 | 1. b4 e5 2. h4 f5 3. e3 Nf6 4. a4 Qg8 |
| S6 | 400 000 000 | 46 | 0 | 1. d4 g5 2. b4 Ng6 3. Nd3 f5 4. c4 a5 |
| S7 | 800 000 000 | 50 | 0 | 1. d4 g5 2. b4 Ng6 3. Nd3 a5 4. bxa5 e5 |
| S8 | 1 600 000 000 | 51 | +3 | 1. d4 a5 2. b4 axb4 3. Bxb4 d6 4. a4 h5 |
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: -5
- Lc0 0.32.1: -14
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 +16, Black +87, difference -71. 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, 9 draws, 1 Black wins, White scored 45.0%.
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. d4 g5 2. b4 Ng6 3. Nd3 f5 4. c4 a5 5. bxa5 e5 |
| 2 | -1 | 41 | 1. b4 e5 2. h4 f5 3. e3 d6 4. a4 Nf6 5. a5 a6 |
| 3 | -12 | 41 | 1. e3 g5 2. d4 f5 3. a4 a5 4. b4 Ng6 5. bxa5 e5 |
Main-line play-out
30 moves, 5 000 000 nodes per half-move. Largest |evaluation| 54 cp, mean 30.3 cp, final -20 cp.
| # | White | cp | Black | cp |
|---|---|---|---|---|
| 1 | d4 | 0 | a5 | +2 |
| 2 | c4 | -10 | d6 | -15 |
| 3 | Nc3 | -19 | Nd7 | -22 |
| 4 | Ba4 | -19 | Rf8 | -15 |
| 5 | f3 | -15 | Nb6 | -34 |
| 6 | Bb3 | -36 | a4 | -35 |
| 7 | c5 | -41 | axb3 | -36 |
| 8 | cxb6 | -40 | c6 | -40 |
| 9 | Nxb3 | -39 | Bxb6 | -39 |
| 10 | Bf2 | -38 | Ra6 | -40 |
| 11 | Qc1 | -44 | f5 | -34 |
| 12 | d5 | -34 | c5 | -30 |
| 13 | Nd2 | -42 | Ba5 | -52 |
| 14 | e4 | -33 | g5 | -54 |
| 15 | e5 | -38 | Qxe5 | -43 |
| 16 | Nc4 | -33 | Qf4 | -36 |
| 17 | Qxf4 | -26 | gxf4 | -32 |
| 18 | Nxa5 | -41 | Rxa5 | -37 |
| 19 | Rb1 | -28 | Bd7 | -40 |
| 20 | O-O | -38 | Kc7 | -32 |
| 21 | a4 | -38 | Bxa4 | -35 |
| 22 | b4 | -33 | cxb4 | -34 |
| 23 | Rxb4 | -35 | b5 | -31 |
| 24 | Ne2 | -32 | Kd7 | -29 |
| 25 | Nxf4 | -25 | Raa8 | -30 |
| 26 | Bd4 | -24 | Nf6 | -27 |
| 27 | Bxf6 | -22 | Rxf6 | -25 |
| 28 | Ne6 | -22 | Rc8 | -14 |
| 29 | Rfb1 | -10 | Rc5 | -23 |
| 30 | Rd4 | -26 | Rh6 | -20 |
Engine self-play
10 games at 500 000 nodes per move: White won 0, drawn 9, Black won 1 — White scored 45.0%. Average length 47.8 moves.
Sample game 1 (1/2-1/2)
1. h4 f5 2. c4 a5 3. d4 d6 4. Nc3 e5 5. Ba4 Nd7 6. Nb3 Ngf6 7. f3 c6 8. d5 cxd5 9. cxd5 Bb6+ 10. Bf2 Bxf2+ 11. Rxf2 Re7 12. e4 Nb6 13. Bb5 a4 14. Nd2 Rc7 15. Qe1 Qd8 16. h5 f4 17. Ndb1 Bd7 18. Na3 Rc8 19. Bxd7 Nbxd7 20. Qf1 Ra5 21. Nc4 Ra6 22. Rc2 Nb6 23. Na3 Ra5 24. Qd3 Rac5 25. b3 axb3 26. axb3 Ra5 27. Ncb1 Rxc2 28. Qxc2 Rc5 29. Qb2 g5 30. hxg6 hxg6 31. Nc3 Nh5 32. Rh3 Qc7 33. Na2 Ra5 34. Kh2 Kc8 35. Nc3 Kd7 36. b4 Ra6 37. Ncb5 Qb8 38. Qf2 Qd8 39. Qh4 Qxh4 40. Rxh4 Ke7 41. Kh3 Ra8 42. Kg4 Kf6 43. Rh1 Rh8 44. Rh4 Nd7 45. Nc4 Kg7 46. Nbxd6 Ndf6+ 47. Kh3 g5
Sample game 2 (1/2-1/2)
1. c4 e5 2. b4 f5 3. h4 d6 4. Ba4 c6 5. c5 dxc5 6. bxc5 Bc7 7. Qb2 Bd7 8. Na3 Nf6 9. Nc4 Qg8 10. d3 Ne6 11. Nxe5 O-O-O 12. Bb3 Qf8 13. Bb4 Kb8 14. Nc4 Bc8 15. Ba3 Nd4 16. Nd6 Nb5 17. Nxe8 Qxe8 18. Bb4 f4 19. Bd1 Be5 20. Qb1 Qe7 21. Nb3 Nd5 22. Bd2 Qf6 23. a4 Nbc3 24. Qc1 Rf8 25. Bxc3 Bxc3 26. Nd2 Bb2 27. Qc2 Bf5 28. Ne4 Qe5 29. Nd2 Qf6 30. Qb3 Re8 31. Qc4 a5 32. Ne4 Bxe4 33. dxe4 Nc3 34. Rh3 Nxe4 35. Rd3 Bc3 36. Rf3 Bb4 37. e3 Qe7 38. Rxf4 Nd2 39. Qf7 Nxf1 40. Kxf1 Bxc5 41. Bc2 h6 42. Ke2 Kc7 43. Qxe7+ Rxe7 44. Bd3 Bd6 45. Rg4 Bc5 46. h5 Ba3 47. Rc4 Re5 48. g4 b5 49. axb5 Rxb5 50. f4 Kb6 51. Bc2 Rc5 52. Rxc5 Kxc5 53. Ba4
Play it in the CH960 app
Open this page on a phone with the CH960 app installed, or find pair 9 / 949 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): rkbbrnnq/pppppppp/8/8/8/8/PPPPPPPP/QNNBBRKR w FHae - 0 1
Mirror twin: White 953 vs Black 10 — a different position (castling squares are fixed), not evaluated by the search.