White 289 vs Black 97

The two setups

White: setup #289 B Q N B R K R N

King on the f-file, rooks on e, g, queen on the b-file; one 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 289 gives White +0.43 (Morozov Balance Index, 400M nodes).

Black: setup #97 B Q N B R N K R

King on the g-file, rooks on e, h, queen on the b-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 97 gives White +0.31 (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 57.

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 0 and +22 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.

For comparison, in symmetric play setup 289 gives White +0.43 and setup 97 gives White +0.31: 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 c4, and 3 first moves are within 10 cp of it.

Along the engine's main line (23 moves) the largest swing was 48 cp (around move 7), 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.

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: 0
• Lc0 0.32.1: +14

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 +142, Black +148, difference -6. 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| 48 cp, mean 15.0 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 29.4 moves.

1. c4 b6 2. b3 c5 3. e3 Qxh2 4. Ng3 e5 5. Bf3 Bxf3 6. gxf3 Qh3+ 7. Ke2 Ng6 8. Kd1 Bc7 9. Nce2 O-O 10. f4 exf4 11. exf4 Bxf4 12. Rh1 Qg2 13. Nxf4 Rxe1+ 14. Kxe1 Re8+ 15. Nfe2 h5 16. Kd1 h4 17. Rg1 Qxf2 18. Rf1 Qh2 19. Rh1 Qf2 20. Rf1 Qh2 21. Rh1 Qg2 22. Rg1 Qf2

1. e4 c5 2. Ng3 h5 3. Bxh5 Bc7 4. Nce2 b5 5. b4 c4 6. d3 d5 7. O-O dxe4 8. dxe4 Nd7 9. h3 Nf6 10. Bf3 Nb6 11. Qc1 Nbd7 12. a4 bxa4 13. Qa3 Ne5 14. Bxe5 Bxe5 15. Qxa4 e6 16. c3 Bc7 17. e5 Bxe5 18. Bxa8 Qxa8 19. Ra1 Nd5 20. Qxa7 Qxa7 21. Rxa7 Nxc3 22. Nxc3 Bxc3 23. Rc1 Bxb4 24. Rxc4 Bd6 25. Ne4 Be5 26. Rca4 f5 27. Nc5 Bf6 28. g3 Rxh3 29. Ra8 Rxa8 30. Rxa8+ Kf7 31. Kg2 Rh5 32. Ra7+ Be7 33. Nd7 Ke8 34. Ne5 Bf6 35. Ra8+ Ke7 36. Ng6+ Kf7 37. Nh8+ Ke7 38. Ng6+ Kf7 39. Nh8+ Ke7

Play it in the CH960 app

Open this page on a phone with the CH960 app installed, or find pair 289 / 97 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): bqnbrnkr/pppppppp/8/8/8/8/PPPPPPPP/BQNBRKRN w EGeh - 0 1

Mirror twin (the same position mirrored): White 379 vs Black 859.

Current place in the live balance rating: 191.