Benoni Defence

Why choose to play 3. ...g6 instead of 3. ...e6?To avoid some variations (eg the Tamainov) or for some other reason?

I don't know this particular opening, but 3..e6 seems oncumfortable for black since the d6 square becomes incurably weak.
g6 on the other hand commits to nothing in the centre but goes for the a1 diagonal and a flank approach (much like a sicilian (an accelerated variation).
Also quick king-safety and white's relatively weak c and d squares are part of the consideration. 4..Bg7 would still make d6 weak (maybe first d6). I don't know how black should solve this, but it looks like black was planning on playing sicilian all along. Though his lack of centre may feel awkward, white is weakening his a1 diagonal for more pressure/space in the centre.

well...,3.  ...e6 is a main line move so this is not becuse it is uncomfortable for black i guess and the 3. ...g6 takes the same time for castling like 3. ..e6 with then Be7...if white doesnt take the pawn... Now about what you said about the sicilian being the first choice,this may be an explanation but i do not think many GMs choose the dragon so why opt for it now?

It may be that black wants to play some KID lines (with the c7-c5 pawn break) but then again why not immediatelly play 2. ...g6?

Black is playing ...g6 in the mainline Benoni anyways, but after having forced the exchange of e6 for c4 which gives him a queenside majority. The reason is to blockade e5.

A plan with ...g6 and ...d6, leaving the white center for a while, does not look obviously wrong to me. It is probably going to transpose into a KID structure later on, though, which is maybe a bad idea (but I do not know).

It is of course to avoid some variations and have some other options, but that's a meaningless statement :-)

I think the point of going ...e6 sooner is that White white will take back on d5 with the c-pawn, so white doesn't have the option of playing e2-e4 and exd5.

Or sometimes why even:

Perhaps it is to maintain the option of entering a czech benoni for another move or two?

Of course I know nothing of Benoni's so it is just a guess.

I used to use that kind of trick - after 1.d4 Nf6 2.c4 e6 I play the Nimzo Indian on 3.Nc3, the Benoni on 3.Nf3. I switched from Benoni to QID on 3.Nf3 though (I simply do not understand the Benoni - sometimes I get in very bad positions without being able to identify the guilty move afterwards).

As for #8, it looks very KID-ish. Of course White has not played e4 and Nf3 yet, but Black still has ...e6 on the table too, so I don't see how this can be bad.

Playing Benoni you want the e-file to be opened and put pressure on e4 and control e5 and d4. If white has time to play e4 and retake with ed5: then does he not have that weaker e-pawn anymore.

That is why I enter the Benoni normally after Nf6, e6 and c5 for black. I want to exchange immediately on d5 forcing white to retake with cd5:. After that can you play d6, preventing white to push his pawn to that field. Disadvantage could be that white can play the Taimanov variation, which is very sharp. But then again, if you play Benoni, then should you like a lot of tactics. It is full of it.

I think that the opening is much too complex for my level to understand what is really going on, but that does not prevent me for liking it to play.

Players that like Bb5 and four pawns stuff with White might be taken out of their game. But like kikvors said White will have the option of killing the game with exd5. Then it's a mad dash for the e-file followed by rook trades and a handshake...

concerning #12 i use it too...if 3.Nf3 -> QID lines if 3.Nc3 -> Benoni

Now about the second diagram,not playing e6 leaves space for the light squre Bishop but even the white can still play f4 e4 e5

Basically there's a couple of plusses and minuses to the 3...g6 move order (which often transposes to the Benoni proper).

The plus is that Black gets to see another White move before deciding whether or not to continue in a KID type vein with ...c5, or whether to try to go back into more Benoni-esque waters with a quick ...e6.

The drawback is that if Black does decide to steer back into a Benoni, White's knight may well be already on c3 allowing him to play e2-e4 and answer a capture on d5 with the e4 pawn (as TitanCG and kikvors alluded to). Black's counterplay is then more restricted than in the traditional Benoni where he aims for b7-b5 - this is the main reason why the ...e6 move order is often preferred, so ensure White has to retake on d5 with his c-pawn.

Hope that helps.

Yes it does thank you,one more thing though...what about 3. ...d6 and then 4. ...g6?

I have another question....at some games the Knight went from b8 to a6 and then to jump to c7,but since white has already played e2-e4 than white can go Bxa6 and create black double pawns but white doesn't play like that...why?

EG

Black tries to finish his development before playing ...e6, thus avoiding early attacks against d6 like in the regular Ben-Oni.

He can play ...e6 later.

Ok got it....but what about the 3rd diagram/question?

My opinion: Benoni is terrible opening. White has much more space, and well.. black gets worse position.

Benko gambit is good: 1.d4-Nf6 2.c4-c5 3.d5-b5

Not quite what i asked for but OK everyone's opinion is important....