Big changes in engine's evaluation after considerable time I hope this question hasn't been asked before.
I am looking for some examples where, say, the latest Stockfish or Komodo engine (or possibly some of the top NN engines) evaluates a position as plus or minus x for some time--possibly oscillating slightly near that point during that period--and then there is a big increase or drop in their evaluation.
What might be a suitable &quot;for some time&quot; period? I want to say more than a minute, but not more than 1 hour. Also, what is a &quot;big&quot; change in evaluation? I am not so sure about that, but let's say something like 3.0.
I am asking this question because, from my (very limited) experience, any dramatic changes in an engine's evaluation occur during the first 20 or so seconds. If an engine cannot find the deep tactics (or the deep positional play) during those first seconds then it is because the search tree has been pruned. (Am I right about this? I don't much about how chess engines operate.)
Edit:
The drastic change in the evaluation should be a consequence of the introduction of a move not previously considered by the engine.
This is a complicated position I had in a correspondence game. White to play and win. The engine evaluation rises and falls, occasionally hitting 0 again. Then it stays at roughly 1.5 for a long while until finally finding the breakthrough about 20 minutes in. Unsurprisingly, considering the full line is pretty insane.
[FEN &quot;r5r1/1np3bk/1p1p4/3P4/bpP2PPp/P3N2P/1q1BQ2K/4R1R1 w - - 0 33&quot;]

1. g5 Rge8 2. Qh5+ Kg8 3. Rg2 bxa3 4. Nf5 Rxe1 5. Bxe1 Bc2 6. Nh6+ Kh8 7. Ng4+ Kg8 8. Nf6+ Kf8 9. Nd7+ Ke7 10. Qg4 Nc5 11. g6 Rh8 12. Re2+ Kd8 13. Nb8 Ba4 14. Nc6+ Bxc6 15. dxc6 Qf6 16. Bf2 Re8 17. Ra2 Qe6 18. Bxh4+ Kc8 19. Re2 Kb8 20. Rxe6 Rxe6 21. Qg2 Re3 22. f5 Be5+ 23. Kg1 Rb3 24. Qa2 Bd4+ 25. Kf1 Rf3+ 26. Kg2 Rb3 27. f6 Rb2+ 28. Kf3 Rxa2 29. g7 Rg2 30. Kxg2 a2 31. g8=Q+ Ka7 32. f7 a1=Q 33. f8=Q Qg1+ 34. Kf3 Qd1+ 35. Kf4 Ne6+ 36. Qxe6 Qf1+ 37. Ke4 Qxf8 38. Qe7 Qxe7+ 39. Bxe7