Loose Slots
Loose slots will have better payoffs to a "certified" high of 100%,
on average over a period time.
A machine will have a symbol, let's say 2-3 cherries, which pays a couple
of coins.
These cherries will replace a symbol that doesn't pay, and presto you have
a loose machine.
In other words, the more paying symbols a machine has, the greater the probability
of payouts - thus a loose slot.