Knowledge Base/Strava Knowledge Base/Strava Segments

Segment Matching Issues

Rosie
posted this on February 02, 2012 04:53 PM

In this article you'll find information on why a segment may not have matched an activity and what to do about it, why false matches occur, and common problems in our segment matching algorithm. 

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 because of GPS drift that occurred during recording of 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. 

Missing the start or endpoint is another common way a segment doesn't match your activity. If the segment is poorly created with endpoints that are inaccurate, it can be hard for other users to match the segment - or if your data has errors that "skip over" or otherwise miss just one of the endpoints.

If you are looking for details about why a specific segment might not have matched your activity - you can try using our new Potential Segment Match Analysis tool.  For more information on this tool, please see our Knowledge Base article.

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 to do:

If a segment should have matched your activity but didn’t please create a support ticket and include a link to the activity and to the segment page and we can try and match it for you. Sometimes we can manually match it for you but unfortunately, in some cases we can’t.

As a side note, creating a segment from your activity and trying to "select" a segment detected as a duplicate in that process will not add the selected segment to your activity. The functionality is simply designed to let you know when duplicate or similar segments exist, not to change what segments will match your activity. 

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. This is due to the way that our segment matching algorithm works and because it must be flexible enough to account for GPS drift. If you’re matched to a segment that is longer or shorter than the stretch of road than you actually covered then your times and speeds for that segment will be inaccurate.

What to do:
If you’d like to be unmatched please create a support ticket and include a link to your ride or segment effort and we can unmatch it for you.

Problematic Segments:

There are certain rules to follow when creating segments that can minimize the amount of problems that segment will experience - including false-positives, missing matches, inaccurate matches, and more.  For detailed information about how to optimize your segment creation, please see this Knowledge Base article

Solutions to Come:

We're actively working to polish our segment matching algorithm - it's certainly a work in progress. We are aware of the issues that can come up with segment matching, and we have solutions to come!

 
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