White 30 vs Black 848

The two setups

White: setup #30 N Q N R K B B R

King on the e-file, rooks on d, h, queen on the b-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 30 gives White +0.14 (Morozov Balance Index, 400M nodes).

Black: setup #848 B B R K N R N Q

King on the d-file, rooks on c, f, queen on the h-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 848 gives White +0.43 (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 59.

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 -31 and +29 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.

For comparison, in symmetric play setup 30 gives White +0.14 and setup 848 gives White +0.43: 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 d4; the alternatives are slightly weaker but keep the game level.

Along the engine's main line (30 moves) the largest swing was 147 cp (around move 30), ending at +140 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.

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 stays within the ±5 cp corridor up to 4 000 000 000 nodes.

Independent engines, run on the same position:

• Berserk 14: -6
• Lc0 0.32.1: 0

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 0, Black +85, difference -85. 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| 147 cp, mean 63.9 cp, final +140 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 41.2 moves.

1. d4 f5 2. f3 Nd6 3. c4 Nxc4 4. e4 Nb6 5. Bd3 fxe4 6. fxe4 Nf6 7. Nab3 Qg8 8. Qc2 Qf7 9. Nd2 c6 10. a4 Qg6 11. Nf3 Nh5 12. Be3 Bf4 13. Bxf4 Nxf4 14. O-O d6 15. Qd2 Nxa4 16. g3 Nxd3 17. Nxd3 Qg4 18. Ng5 Rxf1+ 19. Rxf1 h6 20. Qa5+ Nb6 21. Nf7+ Kc7 22. Nf4 Rf8 23. d5 Rxf7 24. Ne6+ Kd7 25. Rxf7 Qxe4 26. Qxa7 Qxd5 27. Qxb6 Kxe6 28. Rf4 c5 29. Qd8 Qd1+ 30. Kg2 Qe2+ 31. Kg1 Qd1+ 32. Rf1 Qd4+ 33. Rf2 Qd1+ 34. Kg2 Qd5+ 35. Kg1 Qd1+ 36. Kg2 Qd5+ 37. Kf1 Qh1+ 38. Ke2 Qe4+ 39. Kf1 Qb1+ 40. Kg2 Qe4+

1. d4 b6 2. f3 f5 3. c4 e6 4. Nd3 h5 5. Qc2 Nef6 6. Qd2 Ne7 7. Nc2 O-O 8. O-O-O h4 9. Kb1 Qh5 10. Be3 Ng6 11. c5 bxc5 12. dxc5 Bd5 13. Rg1 c6 14. g3 Ne5 15. Nf4 Qf7 16. b3 Bc7 17. gxh4 Rb8 18. Qc3 Nc4 19. Bc1 Be5 20. Nd4 Na3+ 21. Bxa3 Bxf4 22. e3 Bh6 23. Ba6 Qh5 24. f4 Qxh4 25. Ka1 Ng4 26. Rdf1 Qh3 27. Rg3 Qxh2 28. e4 Bxe4 29. Rh3 Qg2 30. Rg3 Qh2 31. Rh3 Qg2 32. Rg3

Play it in the CH960 app

Open this page on a phone with the CH960 app installed, or find pair 30 / 848 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): bbrknrnq/pppppppp/8/8/8/8/PPPPPPPP/NQNRKBBR w DHcf - 0 1

Mirror twin: White 932 vs Black 111 — a different position (castling squares are fixed), not evaluated by the search.

Current place in the live balance rating: 164.