The new formula, the Elo method of calculation adds/subtracts points (as opposed to averaging points) for individual matches to/from a team’s existing point total. The points which are added or subtracted are partially determined by the relative strength of the two opponents, including the logical expectation that teams higher in the ranking should fare better against teams lower in the ranking.
Elo ratings have been used in other sports for decades. A modified version of the Elo rating is currently in use for the FIFA Women’s World Ranking.
The SUM version developed specifically for the new FIFA/Coca Cola World Ranking was fine- tuned to reflect a number of FIFA’s considerations, including the following:
- Adjusting the game weightings to give:
- less importance to friendly matches and more importance to final round competitions, such as the FIFA World Cup Finals
- more importance to knock-out stage matches than group stage matches in final competitions
- Excluding losses in knock-out rounds of final competitions from the calculation
The formula for the SUM algorithm is as follows:
P = Pbefore + I * (W – We)
Pbefore: Points before the match
I: importance of match
I= 0.5 Friendly matches played outside of International Match Calendar windows
I= 1.0 Friendly matches played during International Match Calendar windows
I= 1.5 Group phase matches of Nations League competitions
I= 2.5 Play-off and final matches of Nations League competitions
I= 2.5 Qualification matches for Confederations final competitions and for FIFA World Cup final competitions
I= 3.5 Confederation final competition matches up until the QF stage
I= 4.0 Confederation final competition matches from the QF stage onwards; all FIFA Confederations Cup matches
I= 5.0 FIFA World Cup final competition matches up until QF stage
I= 6.0 FIFA World Cup final competition matches from QF stage onwards
W: result of the match
1 = win; 0.5 = draw; 0 = defeat
We: expected result of the match
We = 1 / (10(-dr/600) + 1), with dr=difference in ratings of the two playing teams, i.e. dr = [Pbefore of Team A – Pbefore of Team B]
