Originally Posted by
murf
One theory I've heard that might hold some water is:
The odds of getting an item when you open a briefcase get worse the more items you have (i.e. getting the first item ~50%, getting the 10th item, ~2% after successful open). Now if you use the timer reset and don't exit the Event screen, the odds won't reset until you are attempt to get the 10th item. So, you maintain the ~50% chance of getting items 1 thru 9 instead of diminishing odds if you exit the event screen and allow your device to re-sync with Gree's server's.
Empirically, I have only tested this once. I accumulated about 30 crates before I began opening them. Then I opened them all never exiting the event screen using the timer reset and gold open option. It only took me 300 gold to get from 1 thru 9, and I spent the rest of a vault of gold without getting the 10th item.
So take this anyway you want.