White 443 vs Black 340
White starts from setup 443 (RNNQBKRB), Black from setup 340 (NBBRKQRN). In the encyclopedia since 2026-10-03: neither side starts better.
|cp| ≤ 5 at 400M · 800M · 1.6B · 4B nodes, two independent engines agree
The two setups
White: setup #443 R N N Q B K R B
King on the f-file, rooks on a, g, queen on the d-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 443 gives White +0.05 (Morozov Balance Index, 400M nodes).
Black: setup #340 N B B R K Q R N
King on the e-file, rooks on d, g, queen on the f-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 340 gives White +0.29 (Morozov Balance Index, 400M nodes).
Why the pair is balanced
At the deepest rungs (400M, 800M, 1.6B nodes) the evaluation never left ±2 centipawns of equality, reaching search depth 54.
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 -5 and +20 cp before settling — a reminder that quick engine checks overstate imbalances, and why the ladder goes deep.
For comparison, in symmetric play setup 443 gives White +0.05 and setup 340 gives White +0.29: 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 c4; the alternatives are slightly weaker but keep the game level.
Along the engine's main line (30 moves) the evaluation stayed within ±25 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.
| Stage | Nodes | Depth | Eval, cp | Main line |
|---|---|---|---|---|
| S0 | 100 000 | 14 | +20 | 1. c4 f5 2. g3 c6 3. d4 Qf7 4. Nd2 f4 |
| S1 | 500 000 | 20 | +2 | 1. c4 c6 2. g3 f5 3. d4 Qf7 4. Qb3 O-O |
| S2 | 2 000 000 | 27 | -2 | 1. c4 c6 2. g3 f5 3. d4 Qf7 4. Qb3 O-O |
| S3 | 8 000 000 | 31 | 0 | 1. c4 e5 2. d4 Qe7 3. dxe5 Ng6 4. Nd3 Nxe5 |
| S4 | 32 000 000 | 35 | -5 | 1. c4 e5 2. d4 Qe7 3. O-O Ng6 4. g3 O-O |
| S5 | 128 000 000 | 41 | -4 | 1. c4 c6 2. g3 f5 3. d4 Qf7 4. Qb3 O-O |
| S6 | 400 000 000 | 50 | +1 | 1. c4 c6 2. g3 f5 3. d4 Qf7 4. Qb3 O-O |
| S7 | 800 000 000 | 51 | 0 | 1. c4 c6 2. g3 f5 3. d4 Qf7 4. Qb3 O-O |
| S8 | 1 600 000 000 | 54 | -2 | 1. c4 e5 2. d4 Qe7 3. dxe5 Ng6 4. Nd3 Nxe5 |
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.
| Nodes | Eval, cp |
|---|---|
| 4 000 000 000 | not checked |
| 8 000 000 000 | not checked |
| 16 000 000 000 | not checked |
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: +7
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 +27, Black +60, difference -33. 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.
| # | Eval, cp | Depth | Main line |
|---|---|---|---|
| 1 | +1 | 42 | 1. c4 c6 2. g3 f5 3. d4 Qf7 4. Qb3 O-O 5. O-O d6 |
| 2 | -19 | 42 | 1. d4 c6 2. g3 d5 3. Nd3 f6 4. Bc3 Qf7 5. Nd2 Nb6 |
| 3 | -22 | 41 | 1. g3 d5 2. d4 c6 3. Nd3 f6 4. Bc3 Qf7 5. Nd2 Nb6 |
Main-line play-out
30 moves, 5 000 000 nodes per half-move. Largest |evaluation| 25 cp, mean 2.3 cp, final 0 cp.
| # | White | cp | Black | cp |
|---|---|---|---|---|
| 1 | c4 | +1 | c6 | -9 |
| 2 | g3 | +1 | f5 | -1 |
| 3 | d4 | 0 | Qf7 | 0 |
| 4 | Qb3 | +3 | O-O | +8 |
| 5 | Ba5 | +5 | Bc7 | +1 |
| 6 | Bxc7 | +3 | Nxc7 | +1 |
| 7 | Nd3 | +1 | d6 | +4 |
| 8 | Nd2 | +17 | Ng6 | +25 |
| 9 | Nf3 | 0 | f4 | 0 |
| 10 | O-O-O | 0 | b5 | -7 |
| 11 | cxb5 | -2 | Qxb3 | -1 |
| 12 | axb3 | 0 | Nxb5 | 0 |
| 13 | h4 | -5 | fxg3 | -2 |
| 14 | Rxg3 | +1 | Nf4 | 0 |
| 15 | Nxf4 | 0 | Rxf4 | 0 |
| 16 | Rdg1 | 0 | g6 | 0 |
| 17 | h5 | 0 | Nxd4 | 0 |
| 18 | Nxd4 | -5 | Rxd4 | -8 |
| 19 | hxg6 | -8 | h5 | 0 |
| 20 | Rg5 | -2 | Rg4 | -1 |
| 21 | R1xg4 | 0 | Bxg4 | 0 |
| 22 | f3 | 0 | Be6 | 0 |
| 23 | Rxh5 | 0 | Kg7 | 0 |
| 24 | Rh7+ | -2 | Kf6 | 0 |
| 25 | f4 | 0 | Bf5 | 0 |
| 26 | Rh6 | 0 | Kg7 | 0 |
| 27 | Rh7+ | 0 | Kf6 | -5 |
| 28 | Rh6 | 0 | c5 | -6 |
| 29 | Kd2 | -5 | e6 | 0 |
| 30 | Bf3 | 0 | d5 | 0 |
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 35.6 moves.
Sample game 1 (1/2-1/2)
1. c4 f5 2. g3 Qf7 3. Qb3 c6 4. d4 O-O 5. Nd3 d6 6. Ba5 Bc7 7. Bxc7 Nxc7 8. Nd2 Ng6 9. Nf3 f4 10. O-O-O b5 11. cxb5 Qxb3 12. axb3 Nxb5 13. h4 h5 14. Nxf4 Nxf4 15. gxf4 Rxf4 16. e3 Rf6 17. Ng5 Nc7 18. f4 Bg4 19. Rde1 Nd5 20. Be4 Rb8 21. Bd3 Nb4 22. Bf1 d5 23. Kd2 c5 24. dxc5 Rc8 25. Bd3 Rxc5 26. Rc1 Rxc1 27. Rxc1 e5 28. Rc7 Nxd3 29. Kxd3 exf4 30. exf4 Rxf4 31. Rxa7 Kf8 32. Ra4 Rf2 33. Ra7 Rf4 34. Ra4 Rf2 35. Kd4 Rxb2 36. b4 Ke7 37. Kxd5 Bd7 38. Ra7 Rxb4 39. Ne4 Rb1 40. Nc5 Rd1+
Sample game 2 (1/2-1/2)
1. g3 c6 2. e4 f5 3. d4 fxe4 4. Bxe4 Qf6 5. Bxh7 Rf8 6. Bd3 Nf7 7. O-O d5 8. f4 g5 9. f5 Qxd4+ 10. Bf2 Qxb2 11. Nb3 Qf6 12. N1d2 Be5 13. Rb1 b6 14. Nf3 Nc7 15. Nxe5 Nxe5 16. g4 c5 17. Bg3 d4 18. Nd2 Nxd3 19. cxd3 Nd5 20. Qf3 Ne3 21. Rfe1 Qh6 22. a4 Bd7 23. Qe2 Bxa4 24. Nc4 Bc6 25. Nxe3 dxe3 26. Qxe3 Qf6 27. Be5 Qf7 28. Bg3 Qf6 29. Be5 Qf7 30. Bg3
Play it in the CH960 app
Open this page on a phone with the CH960 app installed, or find pair 443 / 340 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): nbbrkqrn/pppppppp/8/8/8/8/PPPPPPPP/RNNQBKRB w AGdg - 0 1
Mirror twin (the same position mirrored): White 705 vs Black 334.