Prop betting seeks to proposition the bettor with a question, one that may or may not have a direct bearing on the final score. For example: How many receiving yards will Tyreek Hill have?
The Poisson distribution formula is applied when there is a large number of possible outcomes. For a random discrete variable X that follows the Poisson distribution, and is the average rate of value, then the probability of x is given by: f(x) = P(X=x) = (e-x )/x!