White 430 vs Black 536

The two setups

White: setup #430 R N Q N K B B R

King on the e-file, rooks on a, h, queen on the c-file; no 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 430 gives White +0.39 (Morozov Balance Index, 400M nodes).

Black: setup #536 R B N K B Q N R

King on the d-file, rooks on a, h, queen on the f-file; no 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 536 gives White +0.28 (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 58.

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 shallow rungs wandered between -33 and +6 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.

For comparison, in symmetric play setup 430 gives White +0.39 and setup 536 gives White +0.28: 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 evaluation stayed within ±22 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.

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.

This pair held exactly 0.00 up to 1 600 000 000 nodes.

Independent engines, run on the same position:

• Berserk 14: +6
• Lc0 0.32.1: -3

Independent confirmations: 2 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 -3, Black +29, difference -32. 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.

Main-line play-out

30 moves, 5 000 000 nodes per half-move. Largest |evaluation| 22 cp, mean 9.7 cp, final -6 cp.

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 35.2 moves.

1. e4 e5 2. Ne3 Nge7 3. f3 f5 4. Nc3 c6 5. Qd1 Qf6 6. Qe2 Bc7 7. h4 Nb6 8. a4 a5 9. g4 fxe4 10. fxe4 d5 11. exd5 cxd5 12. Nb5 Bxb5 13. Qxb5 Rf8 14. O-O-O Qc6 15. b3 O-O-O 16. h5 Kb8 17. Qxc6 bxc6 18. c3 Nd7 19. Bd3 g6 20. Nc2 Bd6 21. Rf1 Kc7 22. Be3 Nc5 23. Bxc5 Bxc5 24. b4 Bb6 25. bxa5 Bxa5 26. Na1 e4 27. Be2 Bb6 28. Nb3 c5 29. a5 Ba7 30. c4 d4 31. g5 Kd6 32. Rf6+ Rxf6 33. gxf6 Nc6 34. hxg6 hxg6 35. Bf1 Rb8 36. f7 Ne5 37. Rh7 Rf8 38. Bg2 Nd3+ 39. Kd1 Ke5 40. Nc1 Nf4

1. e4 e5 2. Nbc3 f5 3. f3 c6 4. Ne3 Nce7 5. Nxf5 Nxf5 6. exf5 Qxf5 7. d4 Bg6 8. Bd3 Qe6 9. Bxg6 exd4+ 10. Ne2 Qxg6 11. Bxd4 Ne7 12. Qd2 O-O 13. O-O-O b6 14. Kb1 Qf7 15. h4 Bc7 16. Bf2 Nd5 17. Rhe1 Rae8 18. a3 Be5 19. Nc1 Qf6 20. Nd3 Bc3 21. bxc3 Nxc3+ 22. Kc1 Na2+ 23. Kb1 Nc3+ 24. Kc1 Na2+ 25. Kb1

Play it in the CH960 app

Open this page on a phone with the CH960 app installed, or find pair 430 / 536 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): rbnkbqnr/pppppppp/8/8/8/8/PPPPPPPP/RNQNKBBR w AHah - 0 1

Mirror twin (the same position mirrored): White 724 vs Black 525.