I have taken as many as 5, but the funny thing is that I can pretty well predict which ones I'm going to use, and have never used more than 3 once I got there, and the 3rd ball is always just a few shots in practice just to make sure. I will probably just take two this year, and if I can't figure it out with them, it's not going to happen. For the last several years, especially developing a knowledge of Reno since we've been there so often, for the righties, whether the shot gives you miss room outside or inside, whether the pattern is shorter or longer, really doesn't matter much, the shot is always at 4th or 5th arrow. You can find something somewhere else, but the shot that seems to be the best, lets you stay in the same place the longest, and lends the highest carry percentage is always right there. I always fight it because I don't want to feel like I'm cheating, but I always end up there. I'm taking a Jigsaw Trap and a Taboo, and possibly might drill a Midnight Vibe just in case the shot burns up quickly in doubles so I'll have an option for singles. I don't use plastic, I just flatten my wrist out and use whatever ball I'm using for my first shot at the moment.
So in short, aggressive ball with surface for team, mid range to aggressive pearl for doubles, and depending on the wear and tear on the lanes for singles, either stick with that ball or step down to an entry level to mid range pearl.
That's just like, your opinion, man.