At-risk contributions include time, money, ideas, relationships, supplies, equipment, facilities or anything else someone provides without full payment of it's fair market value. Every day people contribute more and more to a company in hopes that it will someday generate a profit, go public or sell. Because contributions are constantly being made, the model is dynamic. It self-adjusts to stay fair.
There are two basic types of contributions. Cash contributions consume cash, non-cash contributions do not. Unpaid time, for instance, is a non-cash contribution whereas an unreimbursed expense is a cash contribution. Slicing Pie normalizes cash and non-cash contributions by converting to a fictional unit called a "Slice". A slice represents a normalized at-risk contributions. A slice is kind of like a poker chip.
An individuals % share = individual's Slices ÷ all Slices