White 65 vs Black 955
White starts from setup 65 (BNNBRKQR), Black from setup 955 (RKRNBNQB). In the encyclopedia since 2026-10-21: 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. 65, Black by position No. 955, 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 #65 B N N B R K Q R
King on the f-file, rooks on e, h, queen on the g-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 65 gives White +0.26 (Morozov Balance Index, 400M nodes).
Black: setup #955 R K R N B N Q B
King on the b-file, rooks on a, c, queen on the g-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 955 gives White +0.17 (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 -25 and +13 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.
For comparison, in symmetric play setup 65 gives White +0.26 and setup 955 gives White +0.17: 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 b3; the alternatives are slightly weaker but keep the game level.
Along the engine's main line (30 moves) the evaluation stayed within ±24 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 | -25 | 1. b3 a5 2. c4 f5 3. h4 d6 4. d4 a4 |
| S1 | 500 000 | 17 | -4 | 1. b3 d6 2. e3 a5 3. f4 a4 4. Qf2 axb3 |
| S2 | 2 000 000 | 23 | +2 | 1. b3 a5 2. e3 g5 3. Bxh8 Qxh8 4. Nc3 Ng6 |
| S3 | 8 000 000 | 26 | +13 | 1. b3 g5 2. Bxh8 Qxh8 3. Nd3 Ng6 4. e3 d6 |
| S4 | 32 000 000 | 35 | +6 | 1. b3 g5 2. Bxh8 Qxh8 3. Nc3 Ng6 4. e3 d6 |
| S5 | 128 000 000 | 40 | +1 | 1. b3 g5 2. Bxh8 Qxh8 3. Nc3 Ng6 4. Nd3 d6 |
| S6 | 400 000 000 | 47 | +3 | 1. b3 g5 2. Bxh8 Qxh8 3. Nc3 Ng6 4. e3 d6 |
| S7 | 800 000 000 | 49 | +3 | 1. b3 g5 2. Bxh8 Qxh8 3. Nc3 Ng6 4. e3 d6 |
| S8 | 1 600 000 000 | 54 | 0 | 1. b3 g5 2. Bxh8 Qxh8 3. Nc3 Ng6 4. e4 e5 |
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: -8
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 +55, Black +70, difference -15. 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 | 39 | 1. b3 g5 2. Bxh8 Qxh8 3. Nc3 Ng6 4. Nd3 d6 5. e4 e5 |
| 2 | 0 | 39 | 1. f4 f5 2. Qf2 g5 3. fxg5 d6 4. O-O Bd7 5. e4 Nfe6 |
| 3 | -15 | 39 | 1. e3 g5 2. h4 g4 3. f3 f5 4. fxg4 fxg4 5. Qf2 a5 |
Main-line play-out
30 moves, 5 000 000 nodes per half-move. Largest |evaluation| 24 cp, mean 3.4 cp, final 0 cp.
| # | White | cp | Black | cp |
|---|---|---|---|---|
| 1 | b3 | +9 | g5 | +5 |
| 2 | Bxh8 | +12 | Qxh8 | -2 |
| 3 | Nc3 | +3 | Ng6 | +3 |
| 4 | Nd3 | +8 | d6 | 0 |
| 5 | e4 | +3 | e5 | -17 |
| 6 | Bg4 | -17 | Ne6 | -13 |
| 7 | f3 | -12 | a5 | -24 |
| 8 | Qe3 | -8 | h6 | -14 |
| 9 | a4 | -3 | Nd4 | 0 |
| 10 | O-O-O | 0 | Rd8 | 0 |
| 11 | h4 | +12 | gxh4 | +15 |
| 12 | f4 | +19 | exf4 | +5 |
| 13 | Nxf4 | 0 | Nxf4 | 0 |
| 14 | Qxf4 | 0 | b5 | 0 |
| 15 | axb5 | 0 | Nxb5 | 0 |
| 16 | Bf3 | 0 | Nxc3 | 0 |
| 17 | dxc3 | 0 | Qxc3 | 0 |
| 18 | Qxh4 | 0 | Kb7 | 0 |
| 19 | Rd3 | 0 | Qa1+ | 0 |
| 20 | Kd2 | 0 | Qe5 | 0 |
| 21 | Qxh6 | 0 | Bc6 | 0 |
| 22 | Rh5 | 0 | Qa1 | 0 |
| 23 | Qe3 | 0 | Rh8 | 0 |
| 24 | e5 | 0 | Rxh5 | 0 |
| 25 | Bxc6+ | 0 | Kxc6 | 0 |
| 26 | Qe4+ | 0 | Kb6 | 0 |
| 27 | Rc3 | 0 | Rc8 | 0 |
| 28 | Rc6+ | 0 | Ka7 | 0 |
| 29 | Qc4 | 0 | Rxe5 | 0 |
| 30 | Rxc7+ | 0 | Rxc7 | 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 29.0 moves.
Sample game 1 (1/2-1/2)
1. b3 g5 2. Bxh8 Qxh8 3. Nc3 Ng6 4. Nd3 Ne6 5. e4 a5 6. h4 gxh4 7. Nd5 Ng7 8. Qh2 d6 9. N3f4 e6 10. Nf6 Bb5+ 11. c4 Bc6 12. Nxg6 hxg6 13. Qxh4 Ka7 14. f4 Qxh4 15. Rxh4 e5 16. Rh7 Ne6 17. f5 gxf5 18. exf5 Nd4 19. Kf2 Kb6 20. Bh5 Rh8 21. Rxh8 Rxh8 22. g4 Kc5 23. Rf1 b6 24. Ke3 Kb4 25. Bxf7 Rh3+ 26. Kf2 Rf3+ 27. Ke1 Nc2+ 28. Ke2 Nd4+ 29. Ke1 Nc2+ 30. Ke2 Nd4+
Sample game 2 (1/2-1/2)
1. f4 f5 2. b4 a5 3. bxa5 Rxa5 4. Bc3 Ra8 5. Qf2 d6 6. e4 fxe4 7. Rxe4 g5 8. O-O gxf4 9. Bxh8 Qxh8 10. Qxf4 Ng6 11. Qe3 Qa1 12. Qb3 d5 13. Rb4 c5 14. Qb2 Qxb2 15. Rxb2 Ne5 16. Re1 Nc4 17. Rb3 e6 18. Rh3 Bg6 19. d3 Na3 20. Nxa3 Rxa3 21. Rhe3 c4 22. dxc4 Rxe3 23. Rxe3 Rxc4 24. Nd3 Kc7 25. Ne5 Rd4 26. Be2 Be4 27. Bd3 Bxd3 28. Nxd3 Rh4 29. Rg3 Kd6 30. Rg7 e5 31. g3 Rc4 32. Ne1 Rc7 33. Rxc7 Kxc7 34. Kf2 Ne6 35. Nf3 Kd6 36. Ke3 e4 37. Nd4 Nxd4 38. Kxd4 b5 39. g4 Ke6 40. a3 Kf6 41. h4 Kf7 42. c4
Play it in the CH960 app
Open this page on a phone with the CH960 app installed, or find pair 65 / 955 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): rkrnbnqb/pppppppp/8/8/8/8/PPPPPPPP/BNNBRKQR w EHac - 0 1
Mirror twin: White 891 vs Black 1 — a different position (castling squares are fixed), not evaluated by the search.
Current place in the live balance rating: 291.