How ICC Team Rating Works
The rating system is based on the distribution of points to teams for each test match played, so averaging it out over all Tests played by the team throughout the period into consideration. The final rating is, therefore, an average score for the team throughout that period.
The points grant to a team depends on the strength of the opposition. A win against a stronger opposition Give More Point than a win against a weak opposition. The strength of the opposition is set by their rating points at the beginning of the series, and updates happen only at the end of a series, not after every test.
A series win counts as an additional match won. So, if a team wins a series 2-1, once assigning points it’ll count as a 3-1 win.
How Rating Is Calculated
After each test series, the 2 teams receive a particular range of points, supported a mathematical formula. This formula relies on only 2 factors – the series result and also the relative ratings of the 2 teams going into the series. No account is taken of different factors like venue, margin of victory or the importance of the fixture.
every team’s new points total is then divided by its new match/series total to grant an updated rating. With batting averages, if you’re dismissed in your next innings for more than your average, your average can increase.
Conversely, grading but your average can cause it to fall. Similarly, under the ICC test Championship methodology, the points attained from a test win can forever be more than the rating the team had at the beginning of the series.
Equivalently, a team losing a match can always score fewer points than its rating. therefore a win can always boost a team’s rating and a defeat can damage it.
To determine a team’s rating after a particular series:
Find the series result
- Award 1 point to a team for each win
- Award 1/2 point to a team for each draw
- Award 1 bonus point to the team winning the series
- Award 1/2 bonus point to each team if the series is drawn
Convert the series result to actual ratings points
If the gap between the ratings of the two teams at the commencement of the series is less than 40 points, then the ratings points for each team equals:
(The team’s own series result) multiplied by (50 points MORE than the opponent’s rating) PLUS
(The opponent’s series result) multiplied by (50 points LESS than the opponent’s rating)
If the difference in rating points between the two teams at the start of the series is 40 or more points, then the stronger team gets:
- The team’s series points multiplied by 10 points more than the team’s own rating, plus
- The opposition’s series points multiplied by 90 points less than the team’s own rating.
The weaker team gets:
- The team’s series points multiplied by 90 points more than the team’s own rating, plus
- The opposition’s series points multiplied by 10 points less than the team’s own rating
This series score is added to the team’s previous total ratings points, and divided by total number of matches plus series played to arrive at an average score for the team, which is their rating points.
Source – ICC