For example, if you were to toss a handful of 6-sided dice on a table, you would have an equal and unsystematic likelihood of getting a one, two, three, four, five, or six. When I say unsystematic, I mean you aren't throwing the dice and then only choosing the number off of every other dice on the table. When you use a system to randomize the selection instead of just taking the random selections as they fall, then you are not using simple random selection.