Poisson Calculator

Counting stats that occur independently, like threes made, shots on goal, touchdown passes, and corners, tend to follow a Poisson distribution. That means a season average is enough to estimate the odds of any single-game outcome. Enter a player's expected average and a proposition number, and the calculator returns the probability of hitting exactly, at least, or at most that number, with fair odds for each.

This is the quickest way to price a prop from scratch. Say a pitcher is averaging 6.2 strikeouts per start: the Poisson model puts 7 or more Ks at about 42.6%, which works out to fair odds around +135. If a book is hanging over 6.5 strikeouts at +150, you are being paid better than the fair price, making it a value bet. Run any countable stat through the calculator and compare its fair odds against the posted line before you fire.