Segment Matching Checklist

[Mason]

One of the most common questions we see not only in support tickets, but floating around the internet ether is “why didn’t I match a segment”. Once you know what to look for, it’s pretty easy to figure out for yourself why you didn’t match. 

Segments will match to your activity when we detect your activity closely overlaps the path of a segment in the manner in which it was originally created and performed. But let’s face it, GPS isn’t perfect and this segment matching wizardry can be daunting—we are here to help! Below is a checklist to use to help you debug and problem solve.

An example of a segment (red) that doesn't match because I took a different route at the end (in green).

Checklist (roughly in order of frequency)

• Your GPS quality: While we do allow for some amount of GPS inaccuracy, enough of a deviance will be problematic. If your GPS had a bad day and is bouncing on and off the path, it’s much more likely you will not match to the segment. 
• Sport type: Segments only match if the sport types match. Make sure the segment you’re after is the same sport “type” as your activity. You can check the segment sport type by visiting the Segment Details page. 
• Completion of the entire segment: Does your activity cross over the segment start and finish points in the manner in which it was created AND does it stick to that path without deviation? Sometimes even a small detour to a parking lot, bathroom, wrong turn, etc will be enough to disqualify you from matching. This is even the case if you correct your error and head back to complete the rest of the segment.  
• Segment has problematic characteristics: The segment exhibits one or more of the characteristics from this article. These attributes make matching more difficult and sometimes less accurate, especially if they are combined with any of the other factors mentioned on this list. 
• Segment GPS quality: Even if your GPS is smooth and perfectly in line with a path, you can still encounter matching issues. This might happen if a segment was created from an activity with poor quality GPS data. Check the segment’s quality to see if it looks bumpy or off-path. Another indicator a segment’s GPS is problematic is if fewer people than normal are on the leaderboard. Remember, your GPS has to be similarly poor quality for it to match, so the likelihood of having the same errors is low. 
• Correct direction: You must complete a segment in the same direction as it was created. If it’s clockwise, you cannot complete it by going counter-clockwise. You can use the Segment Details Page to note the segment start (in green) and end (checkered flag) to make sure you went that direction. 
• Segment is broken: Sometimes segments have a hiccup and fail to match to older activities. Is the leaderboard empty? This may be a sign the segment is broken. 

Potential Segment Matching Tool

Debugging tool

Did you know we had one? Well, we do! If you log on to the website, you can go to your activity details page and locate the segment section. At the bottom of the page you’ll see the prompt “Don’t see the segment you’re looking for?” This will take you to the activity visualizer where a list of segments appear below. Click on the different segments to see the reasons they were unable to match. You can read more about this tool here. 

Still need help? 

Follow the instructions under the section “How to request a manual match for a missing segment” to submit a support request. 

[eric]

As a segment enthusiast, I will share a tip from my experience. When starting a segment, make sure you didn't just cross the starting point on your way to getting to the start of the segment. Otherwise you may end up with extra time included at the beginning of your segment, because it started when you first crossed that point. If you did, move away from the start point a good distance, I recommend 0.25 mile to be safe. Similarly, when you finish a segment, keep moving past the finish line. If you stop and hang out at the finish point, you might end up crossing the "exact" point later than you intended, and end up with extra time tacked on at the end. In summary - start a ways before the segment starts, and continue beyond the finish. 

[Mason]

@eric Thanks for sharing that tip for others to benefit from. Resting time in segments is a pretty common topic we see in support tickets so we created a help center article for those who want visuals or more information. Check it out here! 

[anchskier]

I wanted to echo what @eric said regarding the starting of segments.  I try to avoid going anywhere near the start of a segment before I am ready to enter it if I am looking for a fast time.  Sometimes it will pick up you being "on" the segment as you pass by the start and still count your time even if you stray away a bit before entering it for real.  

Additionally, keep this kind of thing in mind when creating new segments.  Consider where people will "stage" before starting a segment and also where people are likely to stop after a segment.  Don't create a segment that starts and/or stops at an intersection to natural stopping point.  Start 20 meters into the trail and stop 20 meters before the end (give or take).  Same goes for segments for laps of a ride/race.  Don't start the segment right at the starting line and don't stop it right at the finish line.  If you do that, you often pick up time when people start their devices a little before the gun goes off. 

[Silentvoyager]

There is a type of segment matching issue that I've experienced a few times and that isn't covered by this article. Sometimes a segment does match but includes an extra, unintended time or distance.

There are two possible cases:

1) Hanging right at the segment start or finish. If someone waits right at the segment start, for example to rest before racing that segment, due to GPS drift one of the data points produced while waiting might end up being the closest to the segment start. The same applies to resting right at the segment end after finishing it. In that case the resting time would be included in the matching segment time. I wish Strava handled this situation a bit more intelligently.

2) Here is a more tricky variation of the above case. Imagine finishing a segment and running past its end, but not very far, and then stopping to rest while still within the segment matching radius (e.g. within ~50 meters). Then imagine turning around and returning back past the segment end point. What may happen in this case is that one of the data points on the return path may end up being the closest point to the true segment end. In that case Strava would pick that data point on the return path as the matched end point, adding some extra distance and including the entire resting time. So basically, if someone intends to turn around after finishing a segment, to guarantee a correct segment match they need to go at least 50 meters past the segment end. 

[anchskier]

@Silentvoyager - I run into those scenarios all the time.  There is even a 3rd situation associated with that that is worse than the two you mentioned.  I've had it where I completed the segment, but quick turned around and went back (out and back running intervals for example) and ended up not getting credit at all for completing the segment.  It never thought I finished the segment at all because it never got a data point beyond the finish, it just thought I was still within the segment.  

When I make segments, I always set the start a distance into the trail/course/etc... from an intersection or start line so it won't pick up while someone is waiting before starting.  Same goes for the end, setting it before you get to the typical end point/finish line.  It is all too common to either stop on your own or be forced to stop at an intersection at the end of a segment because others are standing around and you can't get by easily without stopping or slowing way down.  Too many people create their segments to start/stop right at the intersections making this a big issue if you are trying for fast or even representative segment times.  When I am going for a fast time or just want to make sure I get credit for a segment at all, I make sure to go well beyond the end of the segment before stopping.