White 102 vs Black 577
White starts from setup 102 (QNBRNBKR), Black from setup 577 (BQRBNKRN). In the encyclopedia since 2026-10-15: 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. 577, 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 #577 B Q R B N K R N
King on the f-file, rooks on c, g, queen on the b-file; one bishop starts in a corner; the knights start away from the centre. Castling follows the Chess960 rule: king and rook end on the classical squares. In ordinary symmetric play setup 577 gives White +0.14 (Morozov Balance Index, 400M nodes).
Why the pair is balanced
At the deepest rungs (400M, 800M, 1.6B nodes) the evaluation never left ±5 centipawns of equality, reaching search depth 50.
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 +8 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.
For comparison, in symmetric play setup 102 gives White 0.00 and setup 577 gives White +0.14: 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 (30 moves) the largest swing was 53 cp (around move 21), ending at +4 cp — the position stays playable for both sides.
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 | 13 | +8 | 1. b3 c5 2. Bb2 b5 3. e3 O-O 4. h4 b4 |
| S1 | 500 000 | 21 | +2 | 1. c4 c5 2. Nc3 f5 3. e3 O-O 4. d4 cxd4 |
| S2 | 2 000 000 | 22 | -10 | 1. c4 c5 2. Nc3 Ng6 3. h4 h5 4. e3 e6 |
| S3 | 8 000 000 | 29 | -25 | 1. d4 c5 2. dxc5 O-O 3. e3 Ng6 4. h4 h5 |
| S4 | 32 000 000 | 31 | -15 | 1. d4 c5 2. dxc5 Ng6 3. e3 Rxc5 4. b4 Rc8 |
| S5 | 128 000 000 | 37 | -6 | 1. d4 c5 2. dxc5 Ng6 3. e3 Rxc5 4. b4 Rc8 |
| S6 | 400 000 000 | 44 | -5 | 1. d4 Nf6 2. e3 O-O 3. c4 Ng6 4. b3 c5 |
| S7 | 800 000 000 | 46 | 0 | 1. d4 Nf6 2. b4 b6 3. c4 c5 4. bxc5 bxc5 |
| S8 | 1 600 000 000 | 50 | 0 | 1. d4 c5 2. dxc5 Rxc5 3. b4 Rc8 4. e3 b5 |
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: +1
- Lc0 0.32.1: +6
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 +143, difference -62. 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 | -3 | 40 | 1. d4 Nf6 2. e3 b6 3. b3 Ng6 4. h4 h5 5. c4 e6 |
| 2 | -21 | 41 | 1. e3 c5 2. c4 b5 3. cxb5 O-O 4. b3 Ng6 5. Ba3 e5 |
| 3 | -27 | 41 | 1. c4 c5 2. e3 b5 3. cxb5 Ng6 4. b3 O-O 5. Ba3 e5 |
Main-line play-out
30 moves, 5 000 000 nodes per half-move. Largest |evaluation| 53 cp, mean 30.3 cp, final +4 cp.
| # | White | cp | Black | cp |
|---|---|---|---|---|
| 1 | c4 | -14 | c5 | -39 |
| 2 | e3 | -50 | Ng6 | -25 |
| 3 | h4 | -14 | h5 | -22 |
| 4 | Nc3 | -15 | e6 | -18 |
| 5 | b3 | -24 | O-O | -8 |
| 6 | Ne2 | +16 | Nf6 | +27 |
| 7 | Ng3 | +37 | d5 | +36 |
| 8 | Be2 | +38 | d4 | +39 |
| 9 | Rh3 | +47 | b5 | +46 |
| 10 | cxb5 | +48 | e5 | +47 |
| 11 | Nxh5 | +47 | Nxh5 | +41 |
| 12 | Bxh5 | +40 | Qxb5 | +48 |
| 13 | d3 | +41 | Bd5 | +30 |
| 14 | Nf3 | +40 | Be6 | +40 |
| 15 | Rh1 | +35 | Bf6 | +33 |
| 16 | e4 | +31 | a5 | +40 |
| 17 | Bxg6 | +39 | fxg6 | +52 |
| 18 | Ng5 | +50 | Bd7 | +48 |
| 19 | Qb2 | +34 | Rc6 | +35 |
| 20 | a4 | +47 | Qb7 | +52 |
| 21 | Qc2 | +53 | Bxg5 | +48 |
| 22 | Bxg5 | +31 | Be6 | +30 |
| 23 | Rb1 | +32 | Rb8 | +35 |
| 24 | f3 | +32 | Bxb3 | +17 |
| 25 | Qf2 | +18 | Qf7 | 0 |
| 26 | Bd2 | +17 | Rbc8 | +8 |
| 27 | h5 | +10 | gxh5 | +6 |
| 28 | Qg3 | +11 | Bc2 | +12 |
| 29 | Rc1 | +10 | Bxd3 | +6 |
| 30 | Qxe5 | +5 | g6 | +4 |
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 54.2 moves.
Sample game 1 (1/2-1/2)
1. d4 Nf6 2. e3 O-O 3. h4 h5 4. c4 c5 5. dxc5 b5 6. cxb6 Bxb6 7. Nc3 Ng6 8. b4 Ne5 9. c5 Bd8 10. a3 a5 11. Nb5 Ne4 12. Bb2 Ng4 13. f3 Rc6 14. Nd3 Nxe3 15. fxe4 Nxf1 16. Nd6 exd6 17. Bxg7 dxc5 18. Bxf8 Rg6 19. Rxf1 Qg3 20. Nf4 Bf6 21. Rh3 Bxa1 22. Rxg3 Rxg3 23. Rxa1 Kxf8 24. Nxh5 Rb3 25. bxa5 Bxe4 26. Nf6 Bc6 27. Rc1 d6 28. Rd1 d5 29. Nxd5 Rxa3 30. Kf2 Rxa5 31. Ne3 Kg7 32. Rc1 Rb5 33. Kg3 Bd7 34. Kf4 Be6 35. Ke5 Kg6 36. g3 Ra5 37. Nc4 Ra4 38. Ne3 c4 39. Ng2 Ra5+ 40. Kf4 Rf5+
Sample game 2 (1/2-1/2)
1. c4 f5 2. Nc3 Nf6 3. d4 c5 4. dxc5 b6 5. cxb6 Bxb6 6. e3 O-O 7. Be2 Ng6 8. b3 f4 9. O-O Qe5 10. exf4 Nxf4 11. Bxf4 Qxf4 12. Qc1 Qb8 13. Na4 Bc7 14. g3 d5 15. Bf3 Kh8 16. Nc5 Bxg3 17. hxg3 Rxc5 18. Qe3 Ra5 19. Qd2 Qb6 20. b4 Ra4 21. cxd5 Qxb4 22. Qxb4 Rxb4 23. Bg2 Rb5 24. d6 exd6 25. Rxd6 Bxg2 26. Nxg2 Rb2 27. Ra6 Rf7 28. Nf4 h6 29. f3 Kh7 30. Re1 Nd7 31. Ra3 Nb6 32. Re2 Rxe2 33. Nxe2 Nc4 34. Rc3 Ne5 35. Kf2 Rd7 36. Rb3 Rd5 37. Ra3 a5 38. g4 Rd3 39. Rxd3 Nxd3+ 40. Ke3 Nb4 41. Nc3 Kg6 42. a4 Kg5 43. Ne4+ Kh4
Play it in the CH960 app
Open this page on a phone with the CH960 app installed, or find pair 102 / 577 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): bqrbnkrn/pppppppp/8/8/8/8/PPPPPPPP/QNBRNBKR w DHcg - 0 1
Mirror twin: White 854 vs Black 283 — a different position (castling squares are fixed), not evaluated by the search.
Current place in the live balance rating: 418.