How to Read a PR Probability
A PR probability is a statement about repeated attempts under similar conditions — not a promise about today.
The correct interpretation
72 percent means: in roughly seven out of ten attempts under these conditions and with this form, the best time falls. It does not mean you are 72 percent fit or that the wind is 72 percent right.
When the number is unreliable
Three cases to watch. First, a very old best time — the probability may be high simply because you got stronger. Second, a best time set in extreme conditions — hard to beat, which drags the number down. Third, few attempts, meaning a thin basis for estimating your variability.
Deciding with thresholds
Practical thresholds for planning a day:
- under 25 percent: training ride, no attempt
- 25 to 55 percent: take the attempt if you are passing anyway
- 55 to 80 percent: dedicated attempt with warm-up and a plan
- over 80 percent: clear the calendar, this is a record day
In short
Treat PR probability like a weather forecast: useful for planning, never a guarantee.
Frequently asked questions
Why is the PR chance high but the KOM chance near zero?
Because they measure different thresholds. Your own best time is within reach; the KOM time may be a minute faster.
Should I go all-in at 90 percent?
Yes, but with a pacing plan. A high probability does not replace clean execution.