Double Bonus offers increased wins for all four of a kinds with a big pay off for four aces. The variance is almost twice that of Jacks or Better so you will find that Double Bonus is in general a more volatile game where you will experience bigger ups and downs.
The pay table below shows part of the reason why the game is so popular. The full pay version has a pay back of just over 100% coming in at 100.17%.
You have to play five coins to have any chance at getting the highest possible payback