Assuming you mean that you want a 2nd d4 defenst, I think the QGA is an excellent choice. The Grunfeld is theory-heavy, hypermodern, and a great defense with which to try to out-theory or out-play an opponent.
The QGA is kind of the opposite. Can be played on principles, is very straight-forward, and is an excellent choice for when you want to play more conservatively.
The only downside, to my mind, is that it's not one of those, "you can play it against anything white throws at you" kind of defenses, since it pretty much disappears as an option in the absence of d4/c4. So you'd need something independent against the English/Colle/etc.
Hello,
I've decided to make the Grunfeld my main weapon against d4 and have purchased the following books:
The Safest Grunfeld
GM rep 8 Grunfeld vol 1 by Avrukh
GM rep 9 Grunfeld vol 2 by Avrukh
My question though is what would be a good partner defence against d4 to the Grunfeld? I have heard that the QGA Smyslov variation has a Grunfeld feel to it, but have been only able to find 1 book on this by Eric Schiller, and haven't been able to find any reviews for it (I don't buy books generally without reading reviews first).
I have also heard the Semi-Tarrasch has similar pawn structures too, but again haven't been able to find many recent books on this.
Any suggestions of openings to partner the Grunfeld would be welcomed, also if you have any book recommendations to go with them that would be great too!
Thanks for reading,
LostTatctic