In case 5…Ne4 variation of Four Knights Scotch sounds like a mix of various buzzwords, this refers to the first moves 1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. d4 exd4 5. Nxd4 Nxe4 which seems to be dropping a piece, except for it does not.
Alexander Mikhalevski seems to be among the strongest players who ever tried this line, with mixed results as the following two super sharp games illustrate:
Sutovsky, Emil - Mikhalevski, Alexander
1994 , C47
1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. d4 exd4 5. Nxd4 Nxe4 6. Nxe4 Qe7 7. f3 d5 8. Bb5 Bd7 9. O-O dxe4 10. Bxc6 bxc6 11. Re1 O-O-O 12. Rxe4 Qf6 13. Qe2 c5 14. Nb3 Qb6 15. Be3 Bd6 16. Qf2 f5 17. Rc4 Qb5
18. Rc3 c4 19. Bc5 Bc6- ( 19. ... cxb3 20. Bxd6 )
- ( 35. ... Qb2 36. Na6+ Kc8 37. Qxc7# )
Timmerman, Gert - Mikhalevsky, Alexander
1996 , C47
1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. Nxd4 Nf6 5. Nc3 Nxe4 6. Nxe4 Qe7 7. f3 d5 8. Bb5 Bd7 9. Bxc6 bxc6 10. O-O dxe4 11. Re1 O-O-O 12. Rxe4 Qf6 13. Qf1 Bc5 14. Qa6+ Kb8 15. Be3 Rhe8 16. c3 Rxe4 17. fxe4 Bb6
18. a4 c5- Activating the light squared bishop is essential in this structure.
- ( 21. ... dxe3?? 22. Qxc7+ Ka8 23. Qxa7# )
- ( 23. Qa2 Bb7 24. Qa7+ Kc8 )
- In return for the pawn Black gets to activate his pieces, which is always important in positions with bishops of opposite color.