9...

You´ve been told that 9...Ng4?! is second-rate, right? But what´s the punishment, that´s going to offset the two B´s?

Well, look at the squares that 9...Ng4?! has given up (d5/e4). So it´s prob. just trying to establish the Maroczy Bind, but the technique to do this is also important. I dont´think you preface it with (After 10 Bxg4 Bxg4) with 11 f3 first, tho I think I´ve seen 11 f3 recommended. I think you play 11 Nd5! right away, so you can quickly play c4!.

Let´s 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 that´s 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!.

22...Thanx for the howler - just dumping the B.

23...

On 23...Qxf3 24 Rf4 wins.

Note that 24 Bg2? can be answered by 24...Bg5!, when the Black queen escapes. However, 24 Be2 can be played, since 24...Bg5 25 Qxg5 Qxe2 26 Re1 Ne5! 27 Rxe2 Nf3+ 28 Kg2! Nxg5 29 h4! wins. Or...

And, perhaps more instructively:

'Nevertheless, forgetting about 13...b5, the main idea is to answer 13...Be6 with 14 c4!'

Right. And if Black then plays an IMMEDIATE 14...f5! - stripping away the Bind before White has protected c4 and can pop 14...f5! with Nf4? (and then ef).

Then what? White may not have Jack again.

ONCE AGAIN, we see the vital need to examine other people's opening evaluations yourself!