There are still players who believe that the best course of action for black is ....e5 from the O'Kelly. This is rather weak. Against a strong, positional player, black would find his forces cut in half by his own pawn structure and instead of having two very strong bishops, one of them, the dark squared one, would be weak, whether it's inside or outside black's pawn chain. Why deliberately give up the prospect of two good bishops and such a flexible, fluid position, in order to play a system that some GMs mistakenly think is correct, simply because black can just survive? I think that, very often, GMs are the victims of their own tactical ability to survive in sub-par positions. They should perhaps pay more attention to positional aspects and they'd be better players. Certainly, they can be the worst people to teach chess by example, because most others don't have such a well-developed tactical sense, so they need to keep positions relatively simple rather than trying to use complex systems developed by GMs, for GMs. 
The Sicilian Four Knights: A good practical opening?
@Optimissed You play a6 on one move 2. My question is what is your idea behind a6 on move 2. Is there any move order trick?
Since you don't plan to play e5 after d4 cd you have probably another plan in mind.
@Optimissed You play a6 on one move 2. My question is what is your idea behind a6 on move 2. Is there any move order trick?
Since you don't plan to play e5 after d4 cd you have probably another plan in mind.>>>
Sure, e5 Sicilians are a bit stupid if black isn't gaining anything by e5. Like Kasparov, I consider e6 Sicilians stronger, more flexible etc. But against mainline Sicilians with e6, a6, Qc7 and Nf6, defending e4 with Bd3 has long been considered superior to Nc3 because it allows the option of a later c4.
Some people don't like to play against it although there are somewhat complex ways that black can eventually equalise, often based on Bc5. But here, after a6 rather than e6, I would just play Nc6 and if white takes, recapture with dc. Then e5 can be played in one move and of course there's no backward pawn and black gets a good attack on the q-side with the pawns. Black's development is fine because black is a full tempo up on one of the main lines, where e6 has already been played and so black needs to move the pawn again to achieve e5, which is thematic for the position. Using the 2. ...a6 move order I consider black to be very slightly better, whereas after the 2. ...e6 order, black is slightly worse.
Also, 2. ...a6 may tempt white into a c3 Sicilian that he won't know and which is fine for black. I just won one in 3-day today, as a matter of fact. There are other move-order wrinkles to 2. a6 as well. It's vastly under-rated and one day I predict that a GM will legitimise it. Then it will be called after him or her and not after me, because I'm a chess nobody. But I've been playing it for 25 years and my methods are starting to catch on.
@Samhain1966 Can you explain a little more, please? I'm not sure whether I understood everything you say. As far as I undestood you said to two things:
- You avoid playing the open sicilian by not playing 3. d4. For example: 1. e4 c5 2. Nf3 d6 3. Be2.
- The second thing you said which has if I understood correctly nothing to do with the first one since the sicilian four knights requires you to play 3. d4. To be honest I'm not quite sure about what you are trying to say because in most of the lines mentioned above black actually plays in the center. Maybe you can clarify a little bit.
@Samhain1966 Can you explain a little more, please? I'm not sure whether I understood everything you say. As far as I undestood you said to two things:
- You avoid playing the open sicilian by not playing 3. d4. For example: 1. e4 c5 2. Nf3 d6 3. Be2.
- The second thing you said which has if I understood correctly nothing to do with the first one since the sicilian four knights requires you to play 3. d4. To be honest I'm not quite sure about what you are trying to say because in most of the lines mentioned above black actually plays in the center. Maybe you can clarify a little bit.
I apologize for being vague. I suppose I should not have asked a general question on a thread for a specific line. Simply put, is avoiding 3. d4 an acceptable approach? Does it somehow frustrate black?
3.Be2 is fine.
3.Be2 is fine.
Yes, I fail to see why it isn't- e.g. 3...Nf6 4. c3!? transposes to a tricky line, which was played by many whites. Carlsen included!
I play e6 a6 Sicilians although I start from a 2. ... a6 move order. I've noticed that other players on Chess.com are starting to do that too. There's even one in the same group as me in a tournament I've just started to play in. When I see white play a3, it's like a red rag to a bull. It's just asking for ...b5, ...Bb7 and ...b4, preparing to recapture with the f8 bishop, which would still be on f8 ... thus no wasted moves for black. Black is often better by this stage, which is why many players prevent it by a timely a4. Hence a3 is very much a complete waste of a move.