Two Knights Defense 4. Ng5 - Strategy? I've been trying do some research on the defence against 4. Ng5, since it has been a really big thorn in my side for a bit of time.

[FEN ""]
[StartPly "7"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5


I've firstly taken a look into the Traxler attack, but I'm unsure about it since it's such a 'hack' line and well, it's a bit unreliable in a really big match.

I am looking at mainline with Na5 and c6, but I am not quite sure how Black keeps up the initiative from there. His queenside looks a bit shattered and White seems to be fine with happily developing his queenside.

Can anyone tell me some kind of plan or theory on the classical refutation against 4. Ng5?
Thanks!
As someone who plays 4.Ng5 as White, I can tell you what I've found to be the hardest Black line against me: 4...d5 5.exd5 Na5 6.Bb5+ c6 7.dxc6 bxc6 8.Be2 h6 9.Nf3 e4 10.Ne5 Bc5!?

[FEN ""]
1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5 d5 5. exd5 Na5 6. Bb5+ c6 7. dxc6 bxc6 8. Be2 (8. Qf3 Be7 9. Bxc6+ Nxc6 10. Qxc6+ Bd7 11. Qf3 O-O) h6 9. Nf3 e4 10. Ne5 Bc5!? (10...Bd6 11. f4 exf3 12. Nxf3) 11. c3 (11. O-O Qd4 12. Ng4 Bxg4 13. Bxg4 e3) O-O 12. b4 (12. O-O Qc7) Qd5!?


The theory move is 10...Bd6 hitting the knight, but as White I've found that 11.f4 exf3 12.Nxf3 gives White a comfortable enough game a pawn up.

10...Bc5!? takes f4 off the table because of king safety, and Black can attack the near-trapped knight with the queen instead. A main line might be 11.c3 (11.O-O Qd4) O-O 12.b4 (12.O-O Qc7) Qd5!?