Questions on King's Indian Defense

First, what's the idea behind setting up the fianchetto?

second, heres a situation:

(I'm black)

lets say after 1. d4 Nf6 2.c4 g6  white moves d5. whats best possbile move? should I still try to set up the fianchetto? 

Finnaly, what has a better win % as black against the Queen's gambit? the King's Indian or the Queen's Gambit declined?

The KID has a better winning percentage than the QGD.  However, the QGD is easy to learn and play and requires little rote memorization.  If you play solidly, you will get a good position.  I almost drew Varuzhan Akobian in a simul with the QGD. (I missed the opportunity to trade into a drawn rook ending)

After 1.d4 Nf6 2.c4 g6 3.d5, white idea with d5 is to avoid the grundfeld defense. 3...Bg7 is good or you try 3...b5!? an interesting gambit.

i have a question too, how come the kings indian defence is not used anymore, after being used a lot by players such as fischer, kasparov, etc. now its hardly seen. anybody?

i have a question too, how come the kings indian defence is not used anymore, after being used a lot by players such as fischer, kasparov, etc. now its hardly seen. anybody?

I almost crushed Eric Schiller in a simul with the KID :) But I lost because I was so inexperienced. What do you mean what is the idea of the fianchetto? It's like other openings.. Sure it becomes locked in the main line, but it can often activate later in the game or, my personal favorite maneuver Qb8-Bf6-Bd8 and the bishop plays a good defensive roll.

As for an early d5, fianchetto. There is no reason not to, d5 opens up the diagonal for the bishop.  I'm not sure if e5 would be best in that setup but it is probably okay.

 Openings go in and out of fashion.  The KID is a great opening at all levels.  In his excellent (as always) and recent book (2007) "Mastering the Chess Openings - Vol 2" John Watson says of the KID (page 184) "Today the Kings Indian Defense is enjoying a comeback among leading masters after a temporary decline in usage; at the club and tournament level it has never stopped being popular." 

Stay tuned!

You would eventually do the fianchetto following the KID principle. But not when white plays d5. b5 as pvmike suggested, is definitely an interesting gambit. The following line -

3. d5 b5 4. cxb5 a6 would take the game to an interesting level and white would be forced to support the b5 pawn now!

Now you can continue with the fianchetto, depending on the white's move.

thanks!!

ive just followed some of the tournaments that chess.com follows and i usually see the nimzo or the slav come up against d4, i guess i should see more games...

b5 thats the Benko gambit. look at it in wikipedia its a variation thats hard to lose as black if you know how to play it.

It's not quite the Benko gambit

the Benko:

1.d4 Nf6 2.c4 c5 3.d5 b5

KID varation

1.d4 Nf6 2.c4 g6 3.d5 b5

I thought the KID was 1.d4 Nf6 2.c4 g6 3.Nc3 ?

The order of the first few moves can vary in the KID.  Again, I'll quote John Watson "The KID is actually a set of moves that has no specific starting point.  That is to say, Black plays 1 ... Nf6, 2 ... g6,  3 ... Bg7,  4 ... d6 and almost always 0-0 (normally in that order) in that order, versus almost any first move by White other than 1 e4."  (ibid)

Since Black is not contesting the center in the few few moves, he can let White pretty much any move order he wants after 1 d4.  

It's good for white to develop Queenside first. Follow line is interetesting for white. Put pressure to QS;

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.g3 0–0 6.Bg2 e5 7.Nge2

Continue e.g.

7... Nc6 8.d5 Ne7 9.0–0 Nd7 10.Be3 f5 11.exf5 gxf5 12.f4 e4