White 49 vs Black 563
White starts from setup 49 (BNNBRQKR), Black from setup 563 (BRNKNRQB). 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. 49, Black by position No. 563, 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 #49 B N N B R Q K R
King on the g-file, rooks on e, h, queen on the f-file; one 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 49 gives White +0.26 (Morozov Balance Index, 400M nodes).
Black: setup #563 B R N K N R Q B
King on the d-file, rooks on b, f, 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 563 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 ±4 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 -34 and +15 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.
For comparison, in symmetric play setup 49 gives White +0.26 and setup 563 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.
White is not forced into a single path: the best first move is e4, and 2 first moves are within 10 cp of it.
Along the engine's main line (30 moves) the largest swing was 37 cp (around move 1), ending at 0 cp — the position stays playable for both sides.
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 | 13 | +15 | 1. b3 f5 2. h4 g6 3. d4 b5 4. e3 Nf6 |
| S1 | 500 000 | 17 | -1 | 1. h4 f5 2. e3 g5 3. hxg5 Qxg5 4. d4 b6 |
| S2 | 2 000 000 | 24 | -34 | 1. h4 f5 2. b4 b6 3. Nb3 Ncd6 4. e3 g6 |
| S3 | 8 000 000 | 27 | -28 | 1. h4 f5 2. e3 b6 3. d4 g5 4. hxg5 Qxg5 |
| S4 | 32 000 000 | 30 | -7 | 1. e4 g5 2. e5 e6 3. d4 Ne7 4. Qd3 b6 |
| S5 | 128 000 000 | 37 | -9 | 1. e4 g5 2. e5 Ng7 3. d4 b6 4. h4 f6 |
| S6 | 400 000 000 | 44 | 0 | 1. e4 g5 2. e5 e6 3. d4 f6 4. Qd3 b6 |
| S7 | 800 000 000 | 48 | +4 | 1. e4 g5 2. e5 b6 3. d4 Ng7 4. h4 Nf5 |
| S8 | 1 600 000 000 | 50 | 0 | 1. e4 g5 2. e5 c5 3. b4 cxb4 4. c3 b6 |
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: -7
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 +96, Black +171, difference -75. 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 | -15 | 40 | 1. e4 g5 2. e5 Ng7 3. d4 b6 4. b3 Nf5 5. Nd2 Nh4 |
| 2 | -19 | 39 | 1. h4 f5 2. e3 Ncd6 3. d4 O-O-O 4. b3 Nf6 5. Nd3 Nde4 |
| 3 | -42 | 39 | 1. b4 g5 2. Bxh8 Qxh8 3. Nc3 Qd4 4. Nd3 b6 5. h4 g4 |
Main-line play-out
30 moves, 5 000 000 nodes per half-move. Largest |evaluation| 37 cp, mean 15.6 cp, final 0 cp.
| # | White | cp | Black | cp |
|---|---|---|---|---|
| 1 | h4 | -28 | f5 | -37 |
| 2 | e3 | -20 | b6 | -19 |
| 3 | d4 | -12 | Ncd6 | -3 |
| 4 | b3 | +1 | O-O-O | 0 |
| 5 | Bf3 | +9 | Ne4 | +13 |
| 6 | Qe2 | +8 | g6 | +7 |
| 7 | a4 | +15 | e5 | +19 |
| 8 | dxe5 | +26 | d6 | +16 |
| 9 | Nd3 | +19 | dxe5 | +28 |
| 10 | Bxe5 | +25 | Bxe5 | +22 |
| 11 | Nxe5 | +31 | N8f6 | +30 |
| 12 | Nd3 | +32 | Bb7 | +31 |
| 13 | O-O-O | +30 | Qf7 | +31 |
| 14 | Nf4 | +35 | h6 | +30 |
| 15 | Rxd8+ | +33 | Rxd8 | +30 |
| 16 | Nd3 | +20 | Qe7 | +18 |
| 17 | Rd1 | +19 | Kb8 | +19 |
| 18 | Nb2 | +24 | Re8 | +25 |
| 19 | Nc4 | +18 | Ba6 | +21 |
| 20 | Rd4 | +25 | g5 | +16 |
| 21 | g3 | +21 | Rf8 | +19 |
| 22 | Kb2 | +15 | Bxc4 | +13 |
| 23 | Rxc4 | +10 | Qe5+ | +2 |
| 24 | Nc3 | +6 | Nxc3 | 0 |
| 25 | Rxc3 | 0 | gxh4 | 0 |
| 26 | gxh4 | 0 | Ne4 | 0 |
| 27 | Bxe4 | 0 | fxe4 | 0 |
| 28 | b4 | 0 | a5 | 0 |
| 29 | bxa5 | 0 | Qxa5 | +3 |
| 30 | Rc4 | 0 | Qe5+ | 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 38.9 moves.
Sample game 1 (1/2-1/2)
1. e4 g5 2. e5 e6 3. d4 Ne7 4. Qd3 Ng6 5. Qa3 f6 6. Nd3 b6 7. h3 fxe5 8. dxe5 Nh4 9. Rh2 Bb7 10. b4 O-O-O 11. Qxa7 d6 12. Be2 Qf7 13. Nd2 dxe5 14. O-O-O Nd6 15. g3 Nb5 16. Qa4 Nd4 17. Bxd4 Rxd4 18. c3 Rdd8 19. Qa7 e4 20. Nc5 bxc5 21. Ba6 Bxa6 22. Qxa6+ Kd7 23. Qb5+ Ke7 24. Qxc5+ Ke8 25. Qb5+ Qd7 26. Qxd7+ Rxd7 27. gxh4 Rf4 28. hxg5 Bxc3 29. a3 Be5 30. Rg2 Rd3 31. Re1 Rxa3 32. Rxe4 Ra1+ 33. Kc2 Ra2+ 34. Kc1 Ra1+ 35. Kc2 Ra2+ 36. Kb3 Rb2+ 37. Ka4 c5 38. Rg4 Rf5 39. Nb3 Ra2+ 40. Kb5 cxb4
Sample game 2 (1/2-1/2)
1. e4 g5 2. e5 e6 3. d4 Ne7 4. Qd3 Ng6 5. Qa3 f6 6. Nd3 b6 7. h3 fxe5 8. dxe5 Nh4 9. Rh2 Bb7 10. b4 O-O-O 11. Qxa7 d6 12. Be2 Qf7 13. Nd2 dxe5 14. O-O-O Nd6 15. g3 Nb5 16. Qa4 Nd4 17. Bxd4 Rxd4 18. c3 Rdd8 19. Qa7 e4 20. Nc5 bxc5 21. Ba6 Bxa6 22. Qxa6+ Kd7 23. Qb5+ Ke7 24. Qxc5+ Ke8 25. Qb5+ Qd7 26. Qxd7+ Rxd7 27. gxh4 Rf4 28. hxg5 Bxc3 29. a3 Be5 30. Rg2 Rd3 31. Re1 Rxa3 32. Rxe4 Ra1+ 33. Kc2 Ra2+ 34. Kc1 Ra1+ 35. Kc2 Ra2+ 36. Kb3 Rb2+ 37. Ka4 c5 38. Rg4 Rf5 39. Nb3 Ra2+ 40. Kb5 cxb4
Play it in the CH960 app
Open this page on a phone with the CH960 app installed, or find pair 49 / 563 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): brnknrqb/pppppppp/8/8/8/8/PPPPPPPP/BNNBRQKR w EHbf - 0 1
Mirror twin: White 907 vs Black 483 — a different position (castling squares are fixed), not evaluated by the search.
Current place in the live balance rating: 224.