# Tournament FOREcaster: How it works

Updated: August 11, 2011, 8:04 PM ET
ESPN.com

Enjoy playing ESPN.com's Tournament FOREcaster, but want to know how it works? Wonder no longer, as we break down the mathematical equations used to develop our forecasting formula:

In order to generate the win probabilities for each golfer, we use two primary criteria. The first analyzes a golfer's performance during the past five years in which the event was played. The second looks at each golfer's results during the past 10 PGA Tour events in which the golfer has participated.

Using a combination of these items, an average score for each golfer is tabulated, giving higher weightings to more recent performances. From these scores, the probability numbers are generated over three tiers of performance, using a 100 percent pie allotment and driven by a home-grown algorithm involving geometric series and probability distributions. The mathematical model allows all golfers who have satisfied minimum requirements from the two criteria above a chance at winning the tournament.

To ensure integrity of the numbers, the formula was simulated over historical results dating back to 2001 and successfully evaluated against the pre-tournament favorite at the time.