Benoni Defence

Responding to your Na6 question: this is an inmallanced opening.

White have more pawh in kingside, black in queenside. A tipical aproach for black its to try to gain space in queedside and usually a good idea its to try to do b5. There are 2 ways to do that: do a6 to support b5 or do Na6-Nc7.

responding to the other question ( why white do Nd2 ). this is called " knight's tour" variation, the goal its to go in Nc4.

Might i suggest you a nice book about this opening: 

http://www.amazon.co.uk/Modern-Benoni-Chess-Explained/dp/1904600778

I have that book and its very well done.

Greenleaf:  In the line you mentioned where black goes Na6-Nc7 to prep b5, the reason it is not so hot for white to play Bxa6 ...bxa6 to get the doubled a pawns for black is that the b file opens favorably and black gets good counterplay with Rb8 and we notice that the white b pawn is under heavy fire (the Bg7 development makes it quite good).  Chess is a complex game and sometimes we can compromise pawn structure for activity and be ok.  This is a good example.  I've played the benoni for a while and gotten this type of position before with reasonable success

Richard Palliser also has a book on the Modern Benoni that I bought which is very helpful in understanding the main ideas of the opening.  I recommend it (many good example games and tactical puzzles).  Some interesting analysis of the taimanov with sideline option 8...Nbd7 analyzed fairly well (well enough for me to go for it over the mainline Nfd7 even).  I don't think the taimanov is even as good as the Modern MainLine for white.

Tell GMs, apparently they play the Benoni much more often that the Benko. Probably they like bad positions as Black.

For #19 : taking on a6 helps Black by opening the crucial b file, and the black knight is not half as active as the white bishop.

Thanks guys i got it now:)

You're giving up a central pawn, but still for developement... 

What central pawn am i giving up???

I do not know maybe someone more skilled and with  more experience can enilighten us

Mostly, the possibility for White to retake on d5 with the e pawn.

For instance, 1.d4 c5 2.d5 e6 3.e4 (which is not possible in a move order where ...Nf6 is played before).

But I admit I do not know very well the lines.

Oh, and the tricks against an unprepared opponent are not a reason to play an opening.

Pretty sure the Benko has a much better reputation... I may be wrong though.

Can anyone tell me some other thematic moves like Re8 which is almost always played sooner or later,or like Nb8-Na6-Nc7 to prepare b5?It would be really helpful

Good chance you win as black when you can play c4. When the pawns at the b and c file start to role, then will it become very difficult for white.

I have had several times combinations with Bb7xd5 (captures a pawn protected by the pawn on e4).

Next to Nb8-a6-c7 can you play Nbd7 and Ne5 or Nc5.

For white is it important to prevent b5. a4 can be a good move. If white has a knight on c4, then will black have a hard time.

It is good for white to have rooks on the e and c-file.

If white can play e5, then has he a good chance to win the game.

Thanks LoekBergman,very precious tips:)I hope i can learn more and become better at this opening

Thanks Savage:)Concerning your second diagramm though,isn't black sacrifising a pawn?In return for the b-file for the rook?

But still white can place the queen to guard the pinned bishop so...isn't that bad?

Right...but i think then white hasnt lost many so can still give the bishop...though i think then black is better

Sometimes i encounter the Bg5 move which pins the Nf6 knight and i dont know exactly how to face it....i play h6 then g5 kicking the bishop away but then the bishop attcks the d6 square and i cannot place my b-knight on d7 as i would like...any suggestions?

After Kasparov domimated someone that played it against him, everybody was scared to every play it again!

But he also lost a game to Spassky...let alone he himself has used this defence many times against very talented players including Korchnoi

anyone about post #47