For those of you frustrated about repeats in packs when trying to unlock... if you take the time to grind to 50 you'll end up fairly happy I think.
As far as I can tell the way it's coded every gold pack gives you at least one new player.
Sometimes two, but always at least one, most often in the rightmost of the 5 slots.
Post the latest patch 3s are once again easy to hit with a 10 rated 3pt shooter. Good combo for grinding is Steph and then a 10 blocker like David Robinson.
I've got about 15 players left to unlock, but at least now getting a gold pack after each level grind I'm guaranteed to get one. I've found I can grind for a pack in about 10-12 minutes at this point.