Defense of the Fried Liver Attack

There was a thread about a week ago discussing the defense of the Fried Liver.  Here is a game in one of the newer lines touted as white's best shot.  I was defending as black.

I thought 9. a3 was the usual move, I'm sure Estrin recommends it in his book. How is 9. Bb3 an improvement?

p.s. or was it 9. Qe4 c6  10. a3? the memory fades.

I am pretty sure that 9.a3 was proven to be much better for black, although I would need to dig up the line.  This was the proposed improvement in the other thread. 

I like the 9.a3 for white, and believe Black is okay after 9.Bb3

I agree that 9. Bb3 is a mistake.  I think it is too slow.  This seems a good line for black. 9. a3 seems like a good move to me, as has already been suggested.  Another consideration might be 0-0, since white plans to castle there anyway.  One more move on my candidate list might have been 9. d4.  d4 at some point is pretty common in the fried liver.  It attempts to blow open the center such that black's king will find no cover for the rest of the game.

I was suggesting 9.0-0 as white's best line because it is so unclear.

Yes today theory likes 9 0-0.

In every case it's very complicated, but this apparent delay of action by castling is actually very useful, keeping all options open, since there is no immediate mate anyway and it's of course a very desirable move in this type of position!

i read that 6.d4 is an improvement over Nxf7

way back when in one of my first tourneys a couple years ago,  when i played e4, i always played Ng5  against the two knights: heres my best attacking game:

9.a3!

White does not allow his opponent to consolidate his position, and with another sacrifice he continues his attack energetically.  On other moves Black would have more chance to defend himself successfully.

-Palkovi

Can anyone tell me a couple of things in this line.

1) why does Deep Rybka 3 go absolutely nuts for 11...Qh4!? here:

and

since the move scores -1.04 at depth = 15, with 2nd & 3rd choice 11...Kd7 & 11...Kd6 both 0.00

2) why has this never been played before on any database I can find?

I believe this will answer why a3 (not a2, sorry) is better then Bb3... if I'm wrong, it's just my opinion :)

as for 6.d4, I believe thats called the lolli attack and is preferred as a stronger alternative. Google Lolli attack and you'll get more lines on that. I'm still studying it and therefore cant give advice on it :)