White 524 vs Black 739

The two setups

White: setup #524 R B N Q K N B R

King on the e-file, rooks on a, h, queen on the d-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 524 gives White +0.19 (Morozov Balance Index, 400M nodes).

Black: setup #739 B R K N N Q R B

King on the c-file, rooks on b, g, 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 739 gives White +0.04 (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 -16 and +1 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.

For comparison, in symmetric play setup 524 gives White +0.19 and setup 739 gives White +0.04: 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 f3, and 3 first moves are within 10 cp of it.

Along the engine's main line (30 moves) the evaluation stayed within ±19 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: -17

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 +25, Black +111, difference -86. 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| 19 cp, mean 3.3 cp, final 0 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 39.4 moves.

1. f3 b6 2. c3 f5 3. d4 g5 4. a4 g4 5. Nd3 e6 6. Qc2 Nc6 7. Ba2 gxf3 8. gxf3 O-O-O 9. O-O-O Nf6 10. Kb1 Bb7 11. Be3 Kb8 12. Ng3 Ne7 13. Bc1 Bg7 14. a5 Bh6 15. c4 Bxc1 16. Rxc1 Qh6 17. axb6 axb6 18. Ne5 Qh4 19. e4 fxe4 20. c5 Rc8 21. fxe4 Nc6 22. Nxc6+ Bxc6 23. d5 exd5 24. e5 Ng4 25. Nf5 Qg5 26. h4 Qf4 27. cxb6 cxb6 28. Nd6 Ne3 29. Qb3 Kc7 30. Nb5+ Kd8 31. Nd6 Kc7 32. Nb5+ Kb8 33. Nd6

1. a4 b6 2. f3 h5 3. c3 f5 4. d4 g5 5. Ba2 e6 6. Nd3 Nf6 7. Bf2 g4 8. a5 Nf7 9. Ne3 Nd6 10. axb6 axb6 11. Nc4 Nd5 12. Nxd6+ Qxd6 13. Bc4 Bb7 14. Ra7 Ra8 15. Bg3 f4 16. Rxa8+ Bxa8 17. Bxd5 Qxd5 18. Bxf4 d6 19. Be3 Qb5 20. Nb4 Bf6 21. Qd3 Qxd3 22. Nxd3 gxf3 23. gxf3 e5 24. Kd2 Kd7 25. Rf1 Rg2 26. h4 Bd5 27. Rf2 Rg8 28. Rh2 c5 29. dxe5 dxe5 30. b4 c4 31. Nf2 Kc6 32. Bg5 Bxg5+ 33. hxg5 Rxg5 34. Rh4 Bf7 35. Ke3 Rg1 36. Ne4 Kd5 37. f4 exf4+ 38. Kxf4 Rc1 39. Rh3 Rf1+ 40. Rf3 Rg1 41. Ke3 Bg6 42. Nd2 Rc1 43. Kf4 Rg1 44. Ke3 Rc1 45. Kf4 Rg1

Play it in the CH960 app

Open this page on a phone with the CH960 app installed, or find pair 524 / 739 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): brknnqrb/pppppppp/8/8/8/8/PPPPPPPP/RBNQKNBR w AHbg - 0 1

Mirror twin (the same position mirrored): White 540 vs Black 403.