Maximum number of non-pawn pieces on the board In a reachable game, what is the maximum sum of queens, rooks, bishops, knights, and kings on the board?

For queens only, see Maximum number of queens possible
@Aschultz is correct that 26 pieces is the maximum number of non-pawn and non-king pieces on the board. Since they said that they have not seen such proof yet, here it is to be seen.
[Title &quot;me, chess.stackexchange.com 6/18/2019, Non-Unique Proof Game In 40.5 Moves&quot;]
[FEN &quot;&quot;]

1. d4 a5 2. b4 c5 3. h4 e5 4. f4 g5 5. dxc5 axb4 6. hxg5 exf4 7. g4 b5 8. a4 h5 9. c4 f5 10. c6 f3 11. c5 f4 12. g6 b3 13. g7 b2 14. Na3 Nh6 15. g5 b4 16. g6 b3 17. g8=B b1=B 18. Bh7 Ba2 19. g7 b2 20. g8=B b1=B 21. e4 d5 22. e5 d4 23. e6 d3 24. Kd2 Ke7 25. Kc3 Kf6 26. e7 d2 27. Qc2 d1=B 28. e8=B f2 29. c7 f3 30. c6 Bb7 31. Bg2 f1=B 32. c8=B Bfe2 33. Bcd7 f2 34. c7 f1=B 35. c8=B h4 36. a5 Ra6 37. Rh3 Rb6 38. Rg3 h3 39. a6 h2 40. a7 h1=B 41. a8=B