User blog comment:MarimoSwordsman/The Next Straw Hat after Chap 701?/@comment-99.73.79.229-20130312002858

I have a theory. Every time a straw hat joins, the next arc another appears.

East blue saga does not count.

Drum island arc = Chopper Alabasta arc = Robin Post Enies lobby arc = Franky Thriller bark = Brook

So the arc the new straw hat joins, another pops up. Also when Luffy said he wants 10 people to join OSA said Luffy doesn't count himself.