White 519 vs Black 595
White starts from setup 519 (RNBQKNRB), Black from setup 595 (BRQNKRNB). In the encyclopedia since 2026-09-21: 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. 519, Black by position No. 595, 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 #519 R N B Q K N R B
King on the e-file, rooks on a, g, queen on the d-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 519 gives White +0.28 (Morozov Balance Index, 400M nodes).
Black: setup #595 B R Q N K R N B
King on the e-file, rooks on b, 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 595 gives White +0.13 (Morozov Balance Index, 400M nodes).
Why the pair is balanced
At the deepest rungs (400M, 800M, 1.6B, 3.2B nodes) the evaluation is exactly 0.00 each time, reaching search depth 60.
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 -35 and +16 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.
For comparison, in symmetric play setup 519 gives White +0.28 and setup 595 gives White +0.13: 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 g4; the alternatives are slightly weaker but keep the game level.
Along the engine's main line (30 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 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 | 15 | -35 | 1. g4 c5 2. d3 g6 3. c3 b5 4. Bxa8 Rxa8 |
| S1 | 500 000 | 19 | -1 | 1. g4 b5 2. Bxa8 Rxa8 3. d4 g6 4. c3 Rb8 |
| S2 | 2 000 000 | 24 | +1 | 1. g4 b5 2. Bxa8 Rxa8 3. d4 g6 4. e4 Nf6 |
| S3 | 8 000 000 | 31 | -3 | 1. g4 b5 2. Bxa8 Rxa8 3. d4 c5 4. d5 Nf6 |
| S4 | 32 000 000 | 34 | +16 | 1. g4 b5 2. Bxa8 Rxa8 3. d4 Nf6 4. g5 Nh5 |
| S5 | 128 000 000 | 47 | 0 | 1. g4 b5 2. Bxa8 Rxa8 3. d4 d6 4. Nc3 b4 |
| S6 | 400 000 000 | 53 | 0 | 1. g4 b5 2. Bxa8 Rxa8 3. d4 d6 4. Nc3 b4 |
| S7 | 800 000 000 | 52 | 0 | 1. g4 b5 2. Bxa8 Rxa8 3. d4 d6 4. Nc3 b4 |
| S8 | 1 600 000 000 | 57 | 0 | 1. g4 b5 2. Bxa8 Rxa8 3. d4 d6 4. Nc3 b4 |
| S9 | 3 200 000 000 | 60 | 0 | 1. g4 b5 2. Bxa8 Rxa8 3. d4 d6 4. Nc3 b4 |
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 | 0 |
| 16 000 000 000 | 0 |
This pair stays within the ±5 cp corridor up to 16 000 000 000 nodes.
Swap the two setups, giving White the black back rank and Black the white one, and the evaluation jumps to +102. The same two armies dealt the other way round are no longer balanced at all: that is how precisely this pair pays for the first move.
Independent engines, run on the same position:
- Berserk 14: -2
- Lc0 0.32.1: +2
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 +50, Black +102, difference -52. A balanced pair needs White's setup to be weaker by about the price of the first move.
Extended self-play: 160 games, 0 White wins, 160 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 | +2 | 41 | 1. g4 b5 2. Bxa8 Rxa8 3. d4 Nf6 4. g5 Nh5 5. Ng3 Nxg3 |
| 2 | -21 | 40 | 1. g3 g6 2. d3 e6 3. a4 Bg7 4. e4 Ne7 5. a5 b6 |
| 3 | -36 | 40 | 1. a4 b6 2. d4 e6 3. c4 Ne7 4. Nc3 d5 5. cxd5 O-O |
Main-line play-out
30 moves, 5 000 000 nodes per half-move. Largest |evaluation| 25 cp, mean 8.9 cp, final 0 cp.
| # | White | cp | Black | cp |
|---|---|---|---|---|
| 1 | g4 | -2 | b5 | +16 |
| 2 | Bxa8 | +17 | Rxa8 | +16 |
| 3 | d4 | +21 | d5 | +11 |
| 4 | g5 | +18 | g6 | -15 |
| 5 | c3 | +4 | c5 | -25 |
| 6 | Nbd2 | -25 | h5 | -23 |
| 7 | gxh6 | -21 | cxd4 | -16 |
| 8 | cxd4 | -17 | Nxh6 | -12 |
| 9 | Nf3 | -18 | Nf5 | -11 |
| 10 | Ne3 | -8 | Nxe3 | -10 |
| 11 | Bxe3 | -9 | Bf6 | -11 |
| 12 | a4 | -9 | a6 | -12 |
| 13 | Qb3 | -16 | Qc4 | -14 |
| 14 | Nd2 | -5 | Qxb3 | -12 |
| 15 | Nxb3 | -5 | bxa4 | -7 |
| 16 | Nc5 | 0 | Rb8 | -6 |
| 17 | Nxa6 | -10 | Rxb2 | -10 |
| 18 | Nc7+ | -12 | Kd7 | -7 |
| 19 | Nxd5 | -4 | Nc6 | -7 |
| 20 | Bc1 | -4 | Rc2 | -4 |
| 21 | Nb6+ | -5 | Ke8 | -7 |
| 22 | Be3 | -3 | Bxd4 | -11 |
| 23 | Bxd4 | -10 | Nxd4 | -10 |
| 24 | Rxa4 | -6 | e5 | -10 |
| 25 | Ra8+ | -2 | Ke7 | 0 |
| 26 | Nd5+ | 0 | Kd6 | 0 |
| 27 | Rxf8 | 0 | Rc1+ | 0 |
| 28 | Kd2 | 0 | Rxg1 | 0 |
| 29 | e4 | 0 | Nb3+ | 0 |
| 30 | Ke2 | 0 | Nd4+ | 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 36.0 moves.
Sample game 1 (1/2-1/2)
1. g4 b5 2. Bxa8 Rxa8 3. d4 g6 4. e4 Nf6 5. e5 Nd5 6. Bh6 c5 7. Ne3 Qb7 8. Bxf8 Kxf8 9. Nxd5 Qxd5 10. O-O Qxd4 11. Qxd4 cxd4 12. f4 g5 13. Nd2 gxf4 14. Nf3 Nc6 15. Rae1 f6 16. e6 dxe6 17. Rxe6 Rc8 18. c3 dxc3 19. bxc3 Kf7 20. Re4 e5 21. a4 a6 22. Rb1 Rb8 23. Re2 Bg7 24. axb5 Rxb5 25. Rxb5 axb5 26. Ra2 e4 27. Ra6 Ne5 28. Nxe5+ fxe5 29. h4 e3 30. Ra7+ Kf8 31. Ra8+ Ke7 32. Ra7+ Kf8 33. Ra8+ Kf7 34. Ra7+
Sample game 2 (1/2-1/2)
1. g4 b5 2. Bxa8 Rxa8 3. d4 g6 4. e4 Nf6 5. e5 Nd5 6. Bh6 c5 7. Ne3 Qb7 8. Bxf8 Kxf8 9. Nxd5 Qxd5 10. O-O Qxd4 11. Qxd4 cxd4 12. f4 g5 13. Nd2 gxf4 14. Nf3 Nc6 15. Rae1 f6 16. e6 dxe6 17. Rxe6 Rc8 18. c3 dxc3 19. bxc3 Kf7 20. Re4 e5 21. a4 a6 22. Rb1 Rb8 23. Re2 Bg7 24. axb5 Rxb5 25. Rxb5 axb5 26. Ra2 e4 27. Ra6 Ne5 28. Nxe5+ fxe5 29. h4 e3 30. Ra7+ Kf8 31. Ra8+ Ke7 32. Ra7+ Kf8 33. Ra8+ Kf7 34. Ra7+
Play it in the CH960 app
Open this page on a phone with the CH960 app installed, or find pair 519 / 595 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): brqnkrnb/pppppppp/8/8/8/8/PPPPPPPP/RNBQKNRB w AGbf - 0 1
Mirror twin: White 530 vs Black 259 — a different position (castling squares are fixed), not evaluated by the search.
Current place in the live balance rating: 71.