White 237 vs Black 569
White starts from setup 237 (NRQBKNBR), Black from setup 569 (RNKBBNRQ). In the encyclopedia since 2026-10-09: neither side starts better.
|cp| ≤ 5 at 400M · 800M · 1.6B · 4B nodes, two independent engines agree
The two setups
White: setup #237 N R Q B K N B R
King on the e-file, rooks on b, h, queen on the c-file; no 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 237 gives White +0.39 (Morozov Balance Index, 400M nodes).
Black: setup #569 R N K B B N R Q
King on the c-file, rooks on a, g, queen on the h-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 569 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 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 -15 and +18 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.
For comparison, in symmetric play setup 237 gives White +0.39 and setup 569 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 b4; the alternatives are slightly weaker but keep the game level.
Along the engine's main line (26 moves) the largest swing was 55 cp (around move 14), 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 | 12 | -15 | 1. c4 g5 2. b4 f5 3. Nb3 h5 4. Bc2 e6 |
| S1 | 500 000 | 19 | +1 | 1. b4 f5 2. d4 g5 3. Nb3 e5 4. d5 Ng6 |
| S2 | 2 000 000 | 21 | +18 | 1. b4 f5 2. d4 a5 3. bxa5 Nc6 4. Nb3 Nxa5 |
| S3 | 8 000 000 | 26 | +2 | 1. b4 f5 2. f3 g5 3. Nb3 e5 4. e4 f4 |
| S4 | 32 000 000 | 31 | +18 | 1. b4 f5 2. d4 g5 3. Nb3 Ng6 4. h3 Bf7 |
| S5 | 128 000 000 | 46 | 0 | 1. b4 f5 2. d4 g5 3. Nb3 Ng6 4. c4 Nc6 |
| S6 | 400 000 000 | 51 | 0 | 1. b4 f5 2. d4 g5 3. Nb3 Ng6 4. c4 Nc6 |
| S7 | 800 000 000 | 50 | 0 | 1. b4 f5 2. d4 g5 3. Nb3 Ng6 4. c4 Nc6 |
| S8 | 1 600 000 000 | 54 | 0 | 1. b4 f5 2. f3 g5 3. Bf2 e5 4. e4 f4 |
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: -16
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 -21, Black +32, difference -53. 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 | 0 | 44 | 1. b4 f5 2. d4 g5 3. Nb3 Ng6 4. c4 Nc6 5. f3 Nxb4 |
| 2 | -11 | 44 | 1. d4 a5 2. f3 f5 3. c3 e6 4. e4 g5 5. Bc2 g4 |
| 3 | -15 | 44 | 1. f3 a5 2. d4 f5 3. c3 e6 4. Bc2 h5 5. Qd2 a4 |
Main-line play-out
26 moves, 5 000 000 nodes per half-move. Largest |evaluation| 55 cp, mean 13.2 cp, final 0 cp.
| # | White | cp | Black | cp |
|---|---|---|---|---|
| 1 | b4 | +13 | f5 | +1 |
| 2 | f3 | +6 | g5 | -8 |
| 3 | Nb3 | +4 | g4 | 0 |
| 4 | fxg4 | 0 | Rxg4 | 0 |
| 5 | Ng3 | 0 | Qg8 | +15 |
| 6 | e3 | +20 | Rg5 | -4 |
| 7 | Bf2 | 0 | h5 | -6 |
| 8 | Nd4 | -8 | e6 | -10 |
| 9 | Nf3 | -6 | Rg4 | -23 |
| 10 | c4 | -17 | h4 | -17 |
| 11 | Ne2 | -25 | a5 | -11 |
| 12 | b5 | -22 | d6 | -19 |
| 13 | c5 | -8 | dxc5 | -33 |
| 14 | Qxc5 | -37 | Nbd7 | -55 |
| 15 | Qc2 | -38 | Rxg2 | -41 |
| 16 | Rc1 | -31 | Ng6 | -34 |
| 17 | Ned4 | -40 | Nge5 | -24 |
| 18 | h3 | -22 | b6 | -23 |
| 19 | a4 | -17 | Ra7 | -16 |
| 20 | Rf1 | -20 | Kb8 | -17 |
| 21 | Be2 | -9 | Be7 | 0 |
| 22 | Qb3 | 0 | Bf7 | 0 |
| 23 | Nxe5 | 0 | Nxe5 | 0 |
| 24 | Nf3 | 0 | Ng6 | 0 |
| 25 | Nd4 | 0 | Ne5 | 0 |
| 26 | Nf3 | 0 | Ng6 | 0 |
| 27 | 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 33.0 moves.
Sample game 1 (1/2-1/2)
1. b4 g5 2. Nb3 a5 3. bxa5 Nc6 4. Ne3 g4 5. c3 Nxa5 6. Qa3 d5 7. Nxd5 e6 8. Ne3 b6 9. h3 Bc6 10. Qb4 g3 11. fxg3 Rxg3 12. Bf2 Rg8 13. Nxa5 Rxa5 14. Qc4 Rc5 15. Qb4 Rb5 16. Qa4 Rc5 17. Qb4 Rb5 18. Qa4 Rc5
Sample game 2 (1/2-1/2)
1. b4 g5 2. Nb3 a5 3. bxa5 Nc6 4. Ne3 g4 5. c3 Nxa5 6. Qa3 d5 7. Nxd5 e6 8. Ne3 b6 9. h3 Bc6 10. Qb4 g3 11. fxg3 Rxg3 12. Bf2 Rg8 13. Nxa5 Rxa5 14. Qc4 Rc5 15. Qb4 Rb5 16. Qa4 Rc5 17. Qb4 Rb5 18. Qa4 Rc5
Play it in the CH960 app
Open this page on a phone with the CH960 app installed, or find pair 237 / 569 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): rnkbbnrq/pppppppp/8/8/8/8/PPPPPPPP/NRQBKNBR w BHag - 0 1
Mirror twin: White 632 vs Black 489 — a different position (castling squares are fixed), not evaluated by the search.