White 210 vs Black 435

The two setups

White: setup #210 B N Q R K B N R

King on the e-file, rooks on d, h, 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 210 gives White +0.04 (Morozov Balance Index, 400M nodes).

Black: setup #435 B R N N Q K R B

King on the f-file, rooks on b, g, queen on the e-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 435 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 56.

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 agreed early: from 100 thousand to 128 million nodes the evaluation never left ±12 cp.

For comparison, in symmetric play setup 210 gives White +0.04 and setup 435 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.

White is not forced into a single path: the best first move is d4, and 3 first moves are within 10 cp of it.

Along the engine's main line (23 moves) the evaluation stayed within ±29 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: +1
• Lc0 0.32.1: +8

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 +57, Black +110, 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.

Main-line play-out

23 moves, 5 000 000 nodes per half-move. Largest |evaluation| 29 cp, mean 2.8 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 40.8 moves.

1. h4 b5 2. d4 Nd6 3. e3 O-O 4. Nf3 e6 5. b3 Qe7 6. Nbd2 g6 7. c4 bxc4 8. bxc4 f5 9. g3 N8f7 10. Bg2 Ne4 11. O-O Bg7 12. Qc2 Qa3 13. Ne1 g5 14. Nxe4 fxe4 15. Bxe4 Bxe4 16. Qxe4 Qxa2 17. c5 Qd5 18. Qxd5 exd5 19. Rd3 gxh4 20. gxh4 Rb7 21. Ra3 Bf6 22. Nf3 Nh6 23. Bc3 d6 24. Kh1 dxc5 25. Rg1+ Kh8 26. Ra5 Bg7 27. Ne5 cxd4 28. Bxd4 c6 29. Ra6 Rc7 30. Rxg7 Rxg7 31. Rxc6 Nf5 32. Nf7+ Kg8 33. Bxg7 Kxg7 34. Ng5 Rf6 35. Rc7+ Kg6 36. Kh2 d4 37. Rxa7 dxe3 38. fxe3 Nxe3 39. Ra4 Nf5 40. Nh3 Rc6 41. Nf4+ Kf6 42. Nh5+ Kg6 43. Nf4+

1. b3 e5 2. Nf3 d6 3. c4 c5 4. Nc3 O-O 5. e3 Ne6 6. Be2 g6 7. h4 a6 8. h5 b5 9. hxg6 fxg6 10. d3 Nb6 11. Ne4 Qe7 12. Nfd2 Nd7 13. Bf3 Bg7 14. Ke2 Nf6 15. Qc2 Rbd8 16. Rdf1 Nxe4 17. Bxe4 d5 18. cxd5 Bxd5 19. Rc1 Qg5 20. Rh2 h5 21. Bb2 Qf6 22. f3 Bh6 23. Bxd5 Rxd5 24. Ne4 Qe7 25. Rhh1 Rfd8 26. Rcd1 Ng5 27. Nf2 Kh7 28. a3 Bg7 29. Bc1 R5d6 30. Bd2 Rc8 31. Rc1 Rdd8 32. Ba5 Rf8 33. Bb6 Nxf3 34. Bxc5 Nd4+ 35. exd4 Qg5 36. Rcf1 e4 37. Kd1 Bxd4 38. Nxe4 Qg4+ 39. Qe2 Qxe2+ 40. Kxe2 Bxc5 41. Nxc5 Rxf1 42. Rxf1 Rxc5 43. d4 Rg5 44. Ke3 Rxg2 45. d5 Rc2

Play it in the CH960 app

Open this page on a phone with the CH960 app installed, or find pair 210 / 435 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): brnnqkrb/pppppppp/8/8/8/8/PPPPPPPP/BNQRKBNR w DHbg - 0 1

Mirror twin (the same position mirrored): White 647 vs Black 707.