Elo

There are two types of elo used. One for Official matches (belonging to a tournament) and one regular elo, which is changed for every 1-vs-1 match played.

Elo Calculation

Each player starts with a default elo of 1500, and each match played will deduct or add to this value depending on performance.

Change in elo from a given match is calculated using the following formulas

elo_winner = P1(old) + 800 / num_matches * (1 - 1 / (1 + 10 ^ (P2(old) - P1(old) / 400) ) ) * leg_diff_multiplier
elo_looser = P2(old) + 800 / num_matches * (0 - 1 / (1 + 10 ^ (P2(old) - P1(old) / 400) ) ) * leg_diff_multiplier

Where P1 is the winning player, and P2 the looser.

The leg_diff_multiplier is added to distinguish matches won/lost with a big leg difference

multiplier = ln(abs(PD) + 1) * (2.2 / ((P1(old)-P2(old)) * 0.001 + 2.2))

where PD is the point difference of the played match

Additional resources

• https://fivethirtyeight.com/features/introducing-nfl-elo-ratings/
• http://www.eloratings.net/about