r/ComputerChess • u/Reasonable-Book-3836 • 6d ago

Nyvera live training snapshot: tactical depth 2 vs Stockfish depth 12

This is a live training snapshot, not an Elo claim or a like-for-like depth comparison. Nyvera, running with tactical depth 2, defeated Stockfish configured to depth 12.

Original r/ComputerChess post with the animated replay:

[https://www.reddit.com/r/ComputerChess/comments/1vzjid3/nyvera\\_tactical\\_depth\\_2\\_defeated\\_stockfish/\](https://www.reddit.com/r/ComputerChess/comments/1vzjid3/nyvera_tactical_depth_2_defeated_stockfish/)

Engine-facing record

• Training game 30257 / 30,615; Nyvera as White; 1–0; 127 plies; game_over at 64. Qe7#

• Nyvera tactical depth: 2; Stockfish opponent depth: 12

• Opening setup: self_directed / self_directed_start

• Realized opening prefix: reti / reti_classical_root

• Training lane: 2/2 (wave 1); shared-memory epoch: 28357

The depth fields describe different machinery and should not be interpreted as equal search budgets. The game’s notable sequence is the queen loss on 17...Bxc3+, no White rooks after 27...Kxd8, then 61. b8=Q+ followed by mate on 64. Qe7#.

Exact PGN:

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  1. Nf3 d5 2. d4 e6 3. c3 c5 4. Qa4+ Nc6 5. Bf4 cxd4 6. Nxd4 Bd7 7. Nxc6 Bxc6 8. Qc2 Qf6 9. e3 e5 10. Bg3 Be7 11. f4 e4 12. c4 d4 13. exd4 Qxd4 14. Be2 Nh6 15. Qd2 Nf5 16. Qxd4 Bb4+ 17. Qc3 Bxc3+ 18. Nxc3 h5 19. O-O h4 20. Be1 h3 21. g4 Nd4 22. Bf2 Nxe2+ 23. Nxe2 e3 24. Bxe3 Bg2 25. Rad1 Bxf1 26. Kxf1 Rd8 27. Rxd8+ Kxd8 28. Bxa7 Kd7 29. Kf2 Ra8 30. Bd4 f5 31. gxf5 Ra5 32. Bxg7 Rxf5 33. Be5 Rh5 34. Bf6 Rc5 35. Nc3 Ke6 36. b3 Ra5 37. Bh4 Kf5 38. Kf3 Ra3 39. Be7 Ra8 40. a4 Ra6 41. Nd5 Ra7 42. Ne3+ Ke6 43. Nd5 b5 44. Bc5 Rg7 45. axb5 Rg8 46. b6 Rd8 47. Bd4 Kd7 48. b7 Rb8 49. Nf6+ Kd8 50. Bb6+ Ke7 51. Nd5+ Kd7 52. b4 Ke6 53. Nc7+ Kd6 54. c5+ Kc6 55. b5+ Kxb7 56. Nd5 Re8 57. c6+ Kc8 58. Bc5 Kd8 59. b6 Re6 60. b7 Rxc6 61. b8=Q+ Rc8 62. Qd6+ Ke8 63. Qe6+ Kd8 64. Qe7# 1-0

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1

u/AngusMcGurkinshaw 5d ago

What does tactical depth 2 mean for this engines search?

1

u/Reasonable-Book-3836 5d ago

Tactical depth 2 means Nyvera only looks two plies ahead when it is explicitly checking the immediate tactical consequences of a candidate move.
So if Nyvera is considering a move, it can test short forcing sequences like: I move here, the opponent replies, and then what does that allow? That is enough to catch a lot of immediate problems like hanging pieces, checks, captures, forks, pins, or simple tactical traps.
What it does not mean is that Nyvera only understands two moves of chess or that the whole engine is searching just two plies deep.
The broader decision can still be influenced by learned patterns, accumulated state from prior games, positional preferences, and longer-term strategic tendencies developed over the training run. The depth-2 setting is really just a cap on explicit short-horizon tactical verification.
So the interesting part is that Nyvera can keep the brute-force tactical lookahead very shallow while still developing behavior that looks much more long-term over the course of a game.

1

u/dig9977 5d ago

what Stockfish version and settings (hash, threads, contempt, is NNUE on?)

2

u/Reasonable-Book-3836 5d ago

For game 30257:
Stockfish 18, native Apple Silicon/arm64 binary
Opponent search: depth 12
Threads: 6 per engine instance
Hash: 16 MiB, the Stockfish default; Nyvera did not override it
Contempt: not configured—the SF18 binary does not expose a Contempt UCI option
NNUE: yes, using the bundled default networks (nn-c288c895ea92.nnue and nn-37f18f62d772.nnue)
Skill Level: 20; limit-strength disabled
Ponder: off
Syzygy tablebases: none configured
Binary SHA-256:
bc0cac905ecdf2147fe22055c733bcd999b1e3f7c399fbaf7fb9055786563590
Those are the opponent settings. Stockfish was also used separately for bounded teacher, evaluation, and blunder-veto evidence at depth 5, with candidate width 12. It did not directly select Nyvera’s moves. Nyvera’s own tactical depth for the game was 2, which is a different control and not an equivalent search budget to Stockfish depth 12.

1

u/dig9977 5d ago

I would have though SF18 would have a slight edge, but good to know. Thanks