White 188 vs Black 753

The two setups

White: setup #188 N B R N K R B Q

King on the e-file, rooks on c, f, queen on the h-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 188 gives White +0.30 (Morozov Balance Index, 400M nodes).

Black: setup #753 B R K B N N R Q

King on the c-file, rooks on b, g, queen on the h-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 753 gives White +0.19 (Morozov Balance Index, 400M nodes).

Why the pair is balanced

At the deepest rungs (400M, 800M, 1.6B, 3.2B nodes) the evaluation is exactly 0.00 each time, reaching search depth 65.

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 -36 and +24 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.

For comparison, in symmetric play setup 188 gives White +0.30 and setup 753 gives White +0.19: 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 c3, and 3 first moves are within 10 cp of it.

Along the engine's main line (17 moves) the evaluation stayed within ±10 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 stays within the ±5 cp corridor up to 16 000 000 000 nodes.

Swap the two setups, giving White the black back rank and Black the white one, and the evaluation jumps to +61. The same two armies dealt the other way round are no longer balanced at all: that is how precisely this pair pays for the first move.

Independent engines, run on the same position:

• Berserk 14: +6
• Lc0 0.32.1: -11

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 +52, Black +59, difference -7. A balanced pair needs White's setup to be weaker by about the price of the first move.

Extended self-play: 160 games, 0 White wins, 152 draws, 8 Black wins, White scored 47.5%.

Best first moves

The 3 best first moves for White, searched together at 400 000 000 nodes.

Main-line play-out

17 moves, 5 000 000 nodes per half-move. Largest |evaluation| 10 cp, mean 2.9 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 40.4 moves.

1. f3 b6 2. Nb3 g6 3. c3 e5 4. e4 Ne6 5. d4 exd4 6. cxd4 Bg5 7. d5 Bxc1 8. dxe6 Bxb2 9. exf7 Rf8 10. fxe8=Q+ Rxe8 11. Be3 d5 12. O-O dxe4 13. Bxe4 Bxe4 14. fxe4 Rxe4 15. g3 Qe8 16. Rf8 Qxf8 17. Qxe4 Bf6 18. Qe6+ Kb7 19. Qd5+ Kc8 20. Qe6+ Kb7 21. Qd5+ Kc8 22. Nf2 Qe8 23. Ne4 Be5 24. Bd4 Bxd4+ 25. Nxd4 Qd7 26. Qc4 Kb7 27. Nf6 Qd6 28. Ne4 Qd7 29. Nf6 Qd6 30. Ne4

1. c3 e6 2. f3 b6 3. e4 h5 4. Ne3 g5 5. d4 g4 6. f4 Nd6 7. d5 exd5 8. exd5 h4 9. O-O-O Nh7 10. Bf2 Nf6 11. g3 Re8 12. Qg2 Qh5 13. Rfe1 Nfe4 14. Bxe4 Rxe4 15. Nb3 hxg3 16. hxg3 Bf6 17. Qh1 Qg6 18. Qf1 O-O-O 19. Qd3 Rg8 20. c4 Re7 21. Qxg6 Rxg6 22. Nd4 Bxd4 23. Rxd4 Rg8 24. b4 Ree8 25. f5 b5 26. cxb5 Nxb5 27. Rxg4 Nc3 28. Nd1 Nxd1 29. Rxg8 Rxg8 30. Rxd1 d6 31. Rd4 Re8 32. Kd2 Re5 33. g4 a6 34. Bh4 Rxd5 35. Ke3 Bc6 36. a3 Rxd4 37. Kxd4 Bf3 38. g5 Bh5 39. Bg3 Kb7 40. Bf2 Kb6

Play it in the CH960 app

Open this page on a phone with the CH960 app installed, or find pair 188 / 753 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): brkbnnrq/pppppppp/8/8/8/8/PPPPPPPP/NBRNKRBQ w CFbg - 0 1

Mirror twin: White 780 vs Black 395 — a different position (castling squares are fixed), not evaluated by the search.

Current place in the live balance rating: 43.