elohah: Notes...
9...
Youīve been told that 9...Ng4?! is second-rate, right?
But whatīs the punishment, thatīs going to offset the two Bīs?
Well, look at the squares that 9...Ng4?! has given up (d5/e4).
So itīs prob. just trying to establish the Maroczy Bind, but the technique to do this is also important. I dontīthink you preface it with (After 10 Bxg4 Bxg4) with 11 f3 first, tho I think Iīve seen 11 f3 recommended. I think you play 11 Nd5! right away, so you can quickly play c4!.
Letīs see...
10 Bxg4 Bxg4 (btw, after 10...Bxd4!? instead, then 11 Bxd4 Bxg4 12 Be3, does White have more than a minimal plus?; of course 10...Nxd4?? dumps a piece after 11 Bxc8!)
11 f3?! Be6
12 Nd5 Nxd4
13 Bxd4 Bxd4
14 Qxd4 Bxd5
15 exd5 Qb6 (say)
16 Rad1
or 16 Qxb6 axb6
17 Rfe1 Rfe8 (...e5! next)
How big is the advantage, really?
So... 11 Nd5!
Now could Black play 11...Nxd4
12 Bxd4 Bxd4 13 Qxd4 b5! ?
Maybe thatīs the answer. Is there any advantage here at all??
Nevertheless, forgetting about 13...b5, the main idea is to answer 13...Be6 with 14 c4!.
Or again...11 Nd5 e6?! 12 Nc3 Nxd4
13 Bxd4 Bxd4 14 Qxd4 e5?! 15 Qd2! with White looking clearly better, since 15...Qb6? is popped by 16 Nd5! Qd8 (otherwise Black dumps the B) 17 Ne3! (tempo) Be6 18 Rfd1.