As you build up points, the odds of getting a drop increase, and once you get a drop, the points reset. The captains have one guaranteed drop, but the other was either your odds (which improve as you kill invasion captains/minions) were enough to get the second drop, or you had freakishly good luck on that roll.Why didn't the other captains drop 2? I'm not being difficult, I seriously don't know. Is it random for the building points then? Thanks for the info and clarification S_S.