Report
D. Schafer and C. Hayes have written a report on how the rating system works. Note that the report is a work in progress, and is still in a rough draft form. Please do not republish this report without the express written consent of Dan and Calvin.
History
The Foosball Rankings are on their fourth iteration now. The first version used Elo rankings with an instant update system. The major flaw which was exposed was the need to place the games in the exact order in which they were played to ensure accurate ratings. The second iteration used Elo again, this time with all games played in a single week assumed to have been played simultaneously. This system was scrapped due to its extremely unstable nature. The third iteration used the Colley matrix, and featured contrived formulae for margin of victory and weekly depreciation. The fourth and latest version added a mathematically justifiable margin-of-victory formula, and activeness measurements.
