I've been playing the KID the entire time I have been playing chess. I went to the Benko at one time, but gave that up real quick becasue I don't like the declined version. I really like playing different openings so I thought it might be good to find another one against d4. Recently I have been messing around with the Tango, but I don't like white playing Nf3. I refuse to play d5, I just don't like symmetrical openings and the amount of theory. I also like to play aggresively as you could figure out by my name, and so the Grunfeld sort of seems fitting.

So I've looked at some Grünfeld games, and I think it is ok. But I have heard some negative things about it, like you need to memorize a lot of theory. Is this true for, say, USCF C section? And what are the most dangerous, and common lines for black to face? Thanks. I'm willing to play 1.d4 d5, but not very excited about it. I want something that is interesting.

For a long time, I thought the Grunfeld was a ridiculous defense.  Moving your knight three times, giving white that big pawn center before you've even developed a single piece... terrible idea, right?  Then, after years of playing the Nimzo-Indian, and playing around with several other d4 defenses, I gave the Grunfeld a try.  And I *really* liked it.

I find the Grunfeld to consistently create lively, complex games.  I would also say the games are more "open" than any other defense to 1.d4, though in a positional sense rather than classical, if that makes sense.  You definitely need a good sense of how to attack a pawn center, and a solid understanding of the tactical themes to play it successfully.  You can come out of it in great position, or get squashed very horribly.

There is some theory to know, and the exchange lines can be particularly sharp (in addition to the most common).  At USCF Class C, though, I would venture that your opponents are not going to be accustomed to seeing it.  Give it a try... you may find that the tactical considerations are a bit much to manage, or you may find that you like it.

It looks like my kind of defence. Is it something that french defence players like me would like?

The Gruenfeld is OK. Everything is good with equal players, depending on stylistic differences, of course. Everything looks weak against stronger players. Just remember to play d5 on move 3. If 1.d4 Nf6 2.c4 g6 3.Nc3 then d5. Or if 1.c4 Nf6 2.Nc3 then d5 is OK. The point is to play d5 when White has already played Nc3 and before White plays e4. If White leaves out Nc3 by playing Nf3 or g3, Black can still play d5, but cannot respond to 3.cxd5 Nxd5 4.e4 with Nxc3. That is OK, just do not play e6 after White gets in e4 and Nf3 because you may need to play Bg4 to develop and to pressure White's center. Try to avoid e6 if White avoids Nf3. At least "make" White take a tempo for h3.

well if kasparov plays it sometimes, how could it be weak?

so how does black attack white's center?

I enjoyed my brief career with the Grunfeld and am probably going to try it again soon. I switched to the Tarrasch some years ago. Why I can't remember. I think because the book on it was cheaper than the one on the G. You may like the Tarrasch. There are many boring symetrical variations, but there are also many more active ones. It's good to have a few openings you are comforable with.

 It's a combination of pressure from the Bg7, c5 pawn, Nc6, the queen, possibly a Bg4 or Rd8, etc.; black will often complement it with piece pressure on the queenside (Qa5, Rc8, Be6).  Conversely, White's plan is usually to try to roll right down the center behind that wall of pawns.  With the center open, it's usually a pretty fierce fight.

I also play the kings indian all the time however i find it impossible to get good positions against strong players 2000+ so what i play sometimes is d4,d5,c4 bf5 and d4 c5 d5 e5 or f5, both of there openings are not the strongest however i think that black will know them much better than his opponent the majority of the time and are very playable especially against players u2000

the grunfled is a lot more dynamic than the kid and crazier

I prefer Grunfeld to KID, since the fianchetto is immediately shut in in KID and I like active Bishops. I like Benoni as well but when I play against Grunfeld it gives me problems (1 win 1 draw in 20 games) so I'm playing it to get experience

 How Black responds to the white center cannot be identical in every variation of the Gruenfeld. The Exchange and Russian variations are quite different, for example. However, pawn moves are necessary. Often c5 and/or e5 are played. Some schemes also allow for f5. a6 and b5 occur in some lines. Piece play is not the same in each line. Smyslov developed the idea of Nfd7 in the Russian line.

In my experience of playing both the variations KID and Grunfeld, i love both the variations but the difference is the approach KID is the closed postion and Grunfeld is open board positions. Similarities between the linese both are complex variations. Both the variations are suite only for the agreessive style players not for the passive players (Defensive players). Both will give very good entertainment and araise lot of combination in the game. So, we have to be mentally prepared for this. If you deploy any one of this variations your apponent will not comfortable to face this variations. So your getting the psychological edge against them. One more thing both the variation will lead to endings.

If your playing KID in black mostly you will have the inferior position in endings don't get in to the ending soon play your tactics in middle game and go with advantgeous position in ending.

If your playing Grunfeld in black or white it will have unstable positions in the middle game. 

,,gonna try this

Unless you are willing to do some serious study, you are adviced to stay away from the Grunfeld, and use some amateur-friendly opening- say QGD Lasker or Chebanenko Slav. They are both easy to play and understand, and they do not demand absorbing a ton of possible variations.