SP... if you're going to play Chambers Bay I would recommend you bring along some GI-SD balls... you're gonna need the distance and you're gonna need the spin. Especially the spin.
Oh. Or do you use the sneaky range balls to be sneaky long? Someday I'll tell you the story of when (as a kid, of course) I stole a hundred range balls from a driving range (slipped through a fence and gathered them over a hill out of view of the owner) and then sold them back to the owner for 2 cents apiece.