Understand why a segment may not have matched to your activity and what you can do about it, why false matches occur, and common problems in our segment matching algorithm.
How Segment Matching Works
- It's important to keep in mind that each GPS device records its own unique set of data even if, for example, you and your friend are recording the same activity on the same day. When we match you to a segment, we choose the GPS points from your file that fall closest to the segment's start and end. Because of the nature of GPS and the differences in device recording intervals, it's unlikely that there will be a GPS point exactly on top of the segment's start/end. This means that you can be timed over portions of your activity that are slightly longer or shorter than the actual segment length. Everyone is susceptible to this but you may get a short match that works in your favor or a long match that adds a few extra seconds.
- What can I do? The more GPS data points you record, the more options Strava has when choosing a start and end point and the more precise your match is likely to be. Your device's recording interval determines how often you record GPS points. Recording intervals often differ from device to device but if you have the option to set your recording interval we recommend one-second intervals.
A segment didn’t match my activity but it should have
- Why does this happen?
- The most common reason a segment doesn’t match on a ride or run is that GPS drift occurred while you were recording your activity. This can cause you to miss the start or end points of the segment - both of which are necessities - or can cause you to trigger our "Gap Threshold" in the middle of a segment.
- One other possibility is that it is "hidden." There is a link at the bottom of the ride page which may say "Show hidden Segments" You may see the segment listed there - and you can unhide it. For more details, see the article here
- What can I do?
- If you are looking for details about why a specific segment might not have matched your activity, visit the activity on the Strava website and scroll down to the bottom of the list of segments. Click the link 'Don't see the segment you're looking for?' (highlighted below) to open the Potential Segment Match Analysis tool.
- If a segment is missing from your activity when it should have matched please proceed with creating a support ticket and use the Potential Segment Match tool to generate a link. In the analysis tool, select the segment that's missing and copy the link in the address bar of the webpage. Paste the link into the support ticket and repeat this process if there are multiple missing segments.
- Alternatively, you can send us a link to the activity page and the link to the missing segment.
My activity matched a segment that it should not have
- Why does this happen?
- Occasionally a ride or run will be falsely matched to a segment or receive an inaccurate segment time. Sometimes this is due to the fact that our segment matching algorithm must be flexible enough to account for GPS drift and can be a little loose with the matching. Poor GPS data can also contribute to inaccurate segment times. There may also be instances where you received a lift or rode in a vehicle for a portion of your activity and the Crop tool can remove that section of your activity and the invalid segment times.
- What can I do?
- If you’d like to be unmatched please proceed with creating a support ticket and include a link to your ride or segment effort and we can investigate. We can only unmatch segments in cases where it's unlikely there will be future problems with that activity data.
There are certain rules to follow when creating segments that can minimize the number of problems that segment will experience - including false-positives, missing matches, inaccurate matches, and more. We highly suggest avoiding the start or end of a segment if you are going to stop or turn around as the resting time may be included in your segment effort.
Here is some more information on Optimizing Segment Creation.