<<< Back to User Guide

Coach ranking implementation details

A note of caution...

The exact way of calculating the CR of a coach has not been published, what follows below is an old formula for calculating CR. Which at its heart is a version of the ELO ranking system.

The core elements of the formula are still correct, but various modifications and tweaks have changed it over the years. For example it is known that the current formula doesn't include a race modifier, so the strength of the team you play does not affect how many CR points you win or loose when you play.

At the time of updating this it is also known that the current CR system will be replaced with something based on the glicko2 ranking method there is no known timeline for this change.

Summary

Ranking is a mathematically calculated measure of winning ability, and applies to both the coach and the team. A coach or team with a ranking of over 150 is better than average at achieving results that are better than expected, given the strength of his own team and his opponents' teams. A coach or team ranked lower than 150 likewise achieves results that are worse than predicted. Opponent coach rankings are also considered, so drawing against a higher-ranked opponent with equal strength teams will improve the lower-ranked coach's ranking, and degrade the ranking of the higher-ranked coach.

The Mathematics of Rankings

First off, we define a couple of variables:

• Ro = Ranking before match
• Rn = Ranking after match
• K = A division specific "weight" value
• S = Result of game. For a win S = 1.0, for a tie S = 0.5 and for a loss S = 0.0
• p = Win probability
• dR = Difference in ranking (Opponents ranking minus your Ro)
• dT = Normalized difference in team strength ( 100 * [s1/min(s1,s2) - s2/min(s1,s2)] )
• r = A racial modifier by TS

Each team starts with a ranking of 150.0 and after each game, the new Ranking is calculated as follows:

There has been a CR tweak, meaning that p in the first formula is replace by P. This new P is calculated using the old p, as follows:

P = p ^ ( 5 ^ ( 1 - 2*r ) )