In both the game explorer and my chessmaster database, black wins more than white after 1e4 c5 2Nc3 NC6 3 f4. Does this mean it's unsound and that black actually gets the better game? My book recomends this line against the sicilian though. IF black is better then why? Isn't it similar to the main lines except white's knight is behind his f pawn and black's c pawn is still on the board?

Many openings reccomended in books are often considered "iffy" but authors reccomend them because they believe even though it is a second best continuation if your opponant is unprepared then you infact get a better than in most mainline games against them.

so would a grandmaster need to know the ruy lopez and main line sicilians to beat Kasparov for example?

Grand Prix attack is perfectly playable under GM level.But be sure to do Nc3 before the immediate 2.f4.

Grand Prix is ok, its not as hard on black as 2. Nf3 & 3. d4 but it is easier to learn and play.  As stated earlier 1. e4 c5 2. f4 will get you into trouble.

2. f4 is definitely playable for white.

Infact, I know of a line where white has sacrificed his queen playing this opening. The white player was NM Dana Mackenzie.

Used to play it regularly as white before to avoid tera-bites of theory. I've had had good results.

The problem I experienced with it is if the opponent is strong, Black usually holds his position at ease. I get in trouble when my attack steams out because my pawns have been over-extended exposing my king for counter attacks. And the pawns are not easy to defend in the endgame.

The Gran Prix is sound and is used at the GM level. I usually play this way with Black.

or

I don't use the opening myself but it is very sound.

Lets see, Black gets overly ambitious, doesn't play the best line and, by the notes, he passes on a forced draw.   This validates 2. f4 for white? 

Yes, because statistics can't be the only reason to not use an opening. Otherwise everyone would be playing the Ruy Lopez or something.

 All I am showing is a possible line for white. Of course Black does not have to go into this line. I am not saying 2. f4 is the best second move for white but its not his worst and not as bad as you may think.

By the way. If anyone is interested more on this line. You can check a game out here. http://www.danamackenzie.com/game1.htm

I think that's why white plays Nc3 first, to prevent d5 before pushing the f pawn.

Elubas, I think you are right :)

Otherwise black always enjoys knowing he'll at least equalize by move 2, which is always nice ... if you are black. Even Tal played 2...d5 there or recommended it, i forget which. It was a long time ago. For this 2.f4 has been around for a Long time. Even before it had any name. Some English players did get ahold of it, and tried to make something of it. If there is anything good about it, I suppose it must have some from there. Myself, I ignored the entire matter and never seemed to come to any harm from a GranPrix.

I'd hardly call it unsound tho. Just a bit "embarassing" for WT to wonder why he has a pawn sticking out there on f4 after ...d5 is played. Even lines with 2...e6 seem to play well enough against it, {which is hardly a recommendation to the Gran Prix since such "closed French" postions are generally considered not quite so good for Black as "closed Sicilian" positions.} Still like any opening that is not outright unsound, there is always the chance to take something that is perhaps not the sharpest, but learn it better than the next guy, and try to add a few TN's aor Improvements of your own, and forge your own weapon from it that can present chances to win because you do know it better than an opponent. Whether chances come from the opening, middlegame, or ending you can be more familiar with all of them, if you did happen to like playing the type of postions WT gets. Correspondence IM Keith Hayward did that with the Bird's Opening, tho he himself called it a second best opening. But he used it very effectively since it helped bring his IM title. So this is not a "beginner" thing to think about, but can apply at the highest levels.

At your rating I'm sure you are familiar with number of opening choices and know what you like. But let me address this to someone who is considering what to play for perhaps their first opening to study.

I've found Chess is largely about Comfort. The very best must be able to play objectively, even in positions of discomfort, if it is advantageous to them. But anytime there is discomfort it produces more chances for error in most anyone. Very hard to get over the psychology of that. Anytime you enjoy a position, and an opponent does not; whether thru lack of knowlege, or just the asthetics of a position ... then you are almost winning already. It pays to learn what feels good to you at first then build on that, imo. Even GM Bent Larsen suggested building upon strengths first, rather than trying to eliminate all weakness of play. Something like this, "I learn one thing very very well. Then go on and learn to do another thing very well. And that is how to become a GM"  :)