White 102 vs Black 855
White starts from setup 102 (QNBRNBKR), Black from setup 855 (RKBNRNQB). 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. 102, Black by position No. 855, 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 #102 Q N B R N B K R
King on the g-file, rooks on d, 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 102 gives White 0.00 (Morozov Balance Index, 400M nodes).
Black: setup #855 R K B N R N Q B
King on the b-file, rooks on a, e, 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 855 gives White +0.26 (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 55.
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 ±13 cp.
For comparison, in symmetric play setup 102 gives White 0.00 and setup 855 gives White +0.26: 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 d4; the alternatives are slightly weaker but keep the game level.
Along the engine's main line (20 moves) the evaluation stayed within ±25 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 1, drawn 9, Black won 0 (White scored 55.0%).
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 | +13 | 1. h4 d6 2. d4 f5 3. e3 g6 4. b3 Nd7 |
| S1 | 500 000 | 18 | +4 | 1. h4 d6 2. d4 f5 3. b3 h6 4. e3 g5 |
| S2 | 2 000 000 | 24 | -6 | 1. d4 d6 2. h4 g6 3. b3 Nd7 4. Bb2 f5 |
| S3 | 8 000 000 | 31 | -11 | 1. d4 f5 2. h4 d6 3. a4 a5 4. e3 h6 |
| S4 | 32 000 000 | 32 | +12 | 1. d4 g5 2. a4 a5 3. e4 f5 4. exf5 d5 |
| S5 | 128 000 000 | 42 | +10 | 1. d4 d6 2. h4 f5 3. a4 a5 4. e3 Nd7 |
| S6 | 400 000 000 | 45 | 0 | 1. d4 f5 2. h4 d6 3. e3 a5 4. Nc3 g6 |
| S7 | 800 000 000 | 54 | 0 | 1. d4 g5 2. a4 d6 3. a5 a6 4. Nc3 f5 |
| S8 | 1 600 000 000 | 55 | 0 | 1. d4 f5 2. h4 d6 3. e3 a5 4. Nc3 Nd7 |
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: +6
- Lc0 0.32.1: 0
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 +81, Black +133, difference -52. A balanced pair needs White's setup to be weaker by about the price of the first move.
Extended self-play: 10 games, 1 White wins, 9 draws, 0 Black wins, White scored 55.0%.
Best first moves
The 3 best first moves for White, searched together at 400 000 000 nodes.
| # | Eval, cp | Depth | Main line |
|---|---|---|---|
| 1 | +14 | 41 | 1. d4 f5 2. h4 d6 3. e3 a5 4. Nc3 g6 5. b3 Nd7 |
| 2 | -1 | 41 | 1. a4 e5 2. a5 a6 3. e4 d6 4. Bc4 g5 5. d3 Qg6 |
| 3 | -19 | 41 | 1. h4 e5 2. a4 a5 3. Nc3 f5 4. e3 Nfe6 5. Bc4 c6 |
Main-line play-out
20 moves, 5 000 000 nodes per half-move. Largest |evaluation| 25 cp, mean 7.3 cp, final 0 cp.
| # | White | cp | Black | cp |
|---|---|---|---|---|
| 1 | d4 | -12 | d6 | -14 |
| 2 | h4 | -7 | f5 | +9 |
| 3 | e3 | +19 | a5 | +3 |
| 4 | a4 | +17 | g6 | +14 |
| 5 | b3 | +19 | Nd7 | +22 |
| 6 | Bb2 | +25 | Nf6 | +21 |
| 7 | Nd3 | +13 | Nc6 | +11 |
| 8 | c4 | +11 | b6 | 0 |
| 9 | Nd2 | +15 | Nb4 | +11 |
| 10 | c5 | +12 | Bb7 | +9 |
| 11 | Nxb4 | +17 | axb4 | +11 |
| 12 | Bb5 | 0 | Qd5 | 0 |
| 13 | Nf3 | 0 | Qxb3 | 0 |
| 14 | d5 | 0 | bxc5 | 0 |
| 15 | Bxe8 | 0 | Bxd5 | 0 |
| 16 | Bb5 | 0 | c6 | 0 |
| 17 | Rd3 | 0 | Qc2 | 0 |
| 18 | Rd2 | 0 | Qb3 | 0 |
| 19 | Rd3 | 0 | Qc2 | 0 |
| 20 | Rd2 | 0 | Qb3 | 0 |
Engine self-play
10 games at 500 000 nodes per move: White won 1, drawn 9, Black won 0 — White scored 55.0%. Average length 44.1 moves.
Sample game 1 (1/2-1/2)
1. h4 e5 2. c4 Nc6 3. b3 d6 4. Nc3 f5 5. Bb2 Ne6 6. e3 g5 7. Nd5 a5 8. hxg5 Nxg5 9. Be2 Be6 10. Nf3 Nxf3+ 11. Bxf3 Nb4 12. Nxb4 axb4 13. d4 e4 14. Bh5 Bf7 15. Bxf7 Qxf7 16. d5 Bxb2 17. Qxb2 f4 18. exf4 Qxf4 19. Rxh7 e3 20. Rf1 exf2+ 21. Qxf2 Qe4 22. Qf7 Rc8 23. Qf5 Qd4+ 24. Qf2 Qd3 25. Qf5 Qe3+ 26. Qf2 Qd3 27. Rh6 Qc3 28. Rf6 Rh8 29. Rf8+ Rxf8 30. Qxf8+ Ka7 31. Qf6 Qd3 32. Qf5 Qc3 33. Qf6 Qd3 34. Qf5 Qc3
Sample game 2 (1-0)
1. d4 d6 2. e3 g5 3. a4 a5 4. Bb5 Bd7 5. h4 g4 6. g3 f5 7. O-O Nc6 8. c3 e5 9. Na3 Qf7 10. Qb1 Be6 11. b3 Bd5 12. Bc4 Bxc4 13. bxc4 Nd7 14. Nd3 Ra6 15. Rd2 Bf6 16. c5 e4 17. cxd6 exd3 18. dxc7+ Kc8 19. Rb2 Qd5 20. Rxb7 Nb4 21. Rb5 Qf3 22. Qb3 f4 23. Rf5 Bxh4 24. Rxf4 Qd5 25. Qxd5 Nxd5 26. Rf5 Ne7 27. Rh5 Bf6 28. e4 Ng6 29. e5 Bxe5 30. dxe5 Ngxe5 31. Kg2 Kxc7 32. Re1 Rae6 33. Nb5+ Kc8 34. Nd4 Rb6 35. Bf4 Rb2 36. Nf5 Re6 37. Rxh7 d2 38. Rd1 Nc4 39. Ne3 Nxe3+ 40. Bxe3 Ne5 41. Rxd2 Rxd2 42. Bxd2 Nf3 43. Bf4 Re1 44. Rh1 Re4 45. Rh8+ Kd7 46. Rg8 Ne1+ 47. Kf1 Nf3 48. Be3 Rxa4 49. Ke2 Ke6 50. Kd3 Ne5+ 51. Kc2 Kf7 52. Ra8 Ke6 53. Kb3 Ra1 54. Re8+ Kf5 55. Rf8+ Ke6 56. Rf4 Rb1+ 57. Ka4 Ra1+ 58. Kb5 Ra2 59. Bd4 Nd3 60. Rxg4 a4 61. Re4+ Kf7 62. c4 a3 63. Ka4 Rxf2 64. Kxa3 Rd2 65. Kb3 Nc1+ 66. Kc3 Rg2 67. g4 Na2+ 68. Kb3 Nc1+ 69. Kb4 Na2+ 70. Ka4 Nc1 71. c5 Rc2 72. Kb5 Nb3 73. c6 Na5 74. Bc5 Nxc6 75. Kxc6 Rd2 76. Be3 Rd1 77. Kc5 Kf6 78. Kc4 Rd7 79. Rd4 Rg7 80. Kd3 Rg8 81. Ke2 Ra8 82. Rb4 Kf7 83. Kf3 Ke6 84. g5 Kf5 85. Rb5+ Kg6 86. Rb6+ Kf5 87. Rf6+ Ke5 88. Bf4+ Kd4 89. Rd6+ Kc5 90. Be5 Ra3+ 91. Ke4 Ra8 92. g6 Kb4 93. g7 Kc5 94. Rd4 Kb5 95. Bf6 Re8+
Play it in the CH960 app
Open this page on a phone with the CH960 app installed, or find pair 102 / 855 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): rkbnrnqb/pppppppp/8/8/8/8/PPPPPPPP/QNBRNBKR w DHae - 0 1
Mirror twin: White 854 vs Black 98 — a different position (castling squares are fixed), not evaluated by the search.
Current place in the live balance rating: 419.