elohah: 11 e5 Nd7
12 Qh5? fe!
Yet 10 f4 d6! is favorable for Black pretty much for the reason I've stated. Plus about...five more!
Yes...That's about how many points the upcoming move ...b5! will have.
Let's count them:
Chuck, you're welcome to sit in here, as I give the students their education:
(1) Open the b-file against White's King
(2) Establish a knight on b4, thus covering against Bd3
(3) Probably open the a-file as well after allowing ...a5/...a4/...a3, etc.
(4) Place QN in contact with d5, making ...d5 easier.
Look, that's too much already, man, even if I can't remember #5.
Like Bobby said. A3 sucks for White in a Sicilian. He never wanted to play that.
White can try some cipher play on the Kingside to offset all this.
But notice that while Black's cipher play ended in a couple of moves (...b5/...b4), White's will go on...seemingly interminably:
f4 - g4...g5 - what's next? f5? - maybe h4? - what are you doing?
Are you attacking? Defending? Putting your house in order?
You're not even playing Chess, dog.
Now MAYBE you can play the kamikazee sac of g6!! with no support at all, if all your pieces are prepared for that, but that's only because Tal showed you that.
You would have never come up with that on your own, dog.
Not in a million years.