All about the ITRA performance index
General performance index and race category index
The ITRA performance index provides a tool for ranking athletes based on their performance level.
The performance index can be used to compare the level of different trail runners around the world and is built on a scale up to a maximum of 1000 points. The top of the scale corresponds to the theoretical best possible performance.
The general performance index is calculated by obtaining the weighted mean of up to the 5 best results (also called scores) of a runner over the previous 36 months, regardless of the distance category of those 5 races.
The performance index by category is calculated by obtaining the weighted mean of the 5 best results of a runner over the previous 36 months, in a single distance category.
A weighted mean is used because:
- we give more importance to the most recent results compared with older ones,
- we give more importance to a runner’s best result, then their second best, down to their 5th best which has the least influence.
The period of 36 months is long enough to permit reliable statistical calculations and allow an injured runner to continue to appear in the performance index due to their previous performances.
To allow the performance index to be open to as many people as possible, as soon as a runner has completed one race, they appear in the performance index.
Runners who do not have 5 results will still have a PI, which is calculated using their available results. A runner with at least 5 results will have an advantage over someone with less results. For more information see the Performance Index FAQ.
The race categories are based around known typical distances that Trail Runners can find in the majority of the races:
- Half marathon
- 50miles (80kms)
- 100miles (166kms)
- Endurance (beyond 100miles)
For calculation purposes and also because the exact distance of a Trail race usually differs from the distances that are announced due to measurement inconsistencies (different GPS methodlologies etc.) we’ve allowed for a wide enough distance gap when identifying each race category.
For more information see Performance Index FAQ.
How is the runner score calculated?
The score is calculated based on the runner’s finish time and on the specific characteristics of the race he has participated in. The calculation of a score looks only at the finish time and does not use the finish position.
The main characteristics taken into account for each race are distance, elevation gain and loss, and also average altitude.
The technicality of the terrain although important it’s not an objective measure and so our calculation uses an indirect method, based on the statistical analysis of our database of more than 5.3 million individual results to also account for this factor.
This finish time is then compared with a theoretical best possible performance for that race and a score is awarded. Scores are built on a scale up to a maximum of 1000 points with the top of the scale corresponding to the theoretical best possible performance.
For more information see the Race Score FAQ.