Before meets start next week, I wanted to take the opportunity to give a brief explanation/ introduction to what speed ratings are and how they can be used. On the “What are speed ratings” page it gives a brief explanation, also this article from Tullyrunners.com does a pretty good job as well.
Speed ratings are a number that tells you the relative speed compared to all other runners. This number can be used to tell the time difference between two runners. Rule of thumb is that 1 speed rating point is equal to 3 seconds. I calculate the race adjustments or speed of the race to calculate the ratings. I typically use the 5 years of history I have to check the reasonableness of my adjustments, but also later in the season I am able to compare the ratings with seasonal averages to see if the adjustment is in line.
The goal of speed ratings is not to predict what the actual time of a runner will be but to give an estimate to where different runners will match up in a race all things being equal.
Common questions:
“How come the ratings are different on the same course but different race?”
The answer to this is the ratings are not calculated based on the course, but the actual race itself. A race in August vs. a conference meet on the same course in October are going to have drastically different speeds. The conference race will typically have a higher adjustment because it is faster, meaning that a time run in August vs. the same time run in October will have a higher rating that the time in October.
“How does weather or course condition affect the rating calculation?”
The ratings do take weather and course conditions into account based on the pace of the race. If the conditions are sloppy, the races are going to be slower which leads to a lower adjustment when the ratings are calculated.
Please reach out if you have further questions.
