Automatically flag blatantly impossible things

There are a significant amount of activities that have what I will call impossible results. There are quite a few reasons why this could happen, including bad GPS data, wrong activity type, using a car, etc. Strava should implement some checks to automatically flag blatantly impossible things that are well beyond the capabilities of human performance like sub 3 minute running miles, or tens of thousands of feet of gain in an hour long run.

The leaderboards of the monthly running climbing challenges are frequently garbage results from random athletes whose watches recorded crazy elevation gains on what are almost always completely flat runs. It would be easy to check their VAM against known world best performances and see that such gain is literally 10 times more than the world's best mountain runners could do in that time period. Or simply do a GPS spot check against the altitude data that their watch recorded, often altitudes of over 20,000 ft (and they aren't in the Himalayas, Denali, or the Andes).

There are many similar threads to this, some that are quite old. I really don't know why Strava has not fixed this yet.

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  • Comentario oficial

    Currently, we do have an auto-flag system in place. The system works to detect when an uploaded activity ranks 1st on any segment leaderboards by an amount considered unlikely (based on how many athletes have matched the segment, either 25% faster or 50% faster than the existing fastest time). 

    We would love to improve this system and make the auto-flagging more robust and accurate. We appreciate the feedback and will keep you all informed when development on this system is planned. 

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  • I agree, and I always make that comment when flagging KOMs ridden at 70 mph, when the previous KOM was 15, for example.  My solution was to cease my premium membership.  If strava doesn't listen to suggestions, perhaps they'll listen to dollars.

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  • Just cancelled Strava Premium, as this is the most important feature that looks like it will never be introduced.
    I did a run yesterday and checked my progress on a few segments only to find 80+ cyclists registering impossible "running" times on the segments.

    I am not going flagging 80+ activities, Strava should be auto flagging better than world record running activities.

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  • Agreed! Any mile split during a run that breaks a WR should be automatically flagged.

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  • Let's take a look at the current US leaderboard for the January Run Climbing Challenge place by place:

    1. Has a private profile, but has done 102,000' of gain in 4h25m of running. Not legit.

    2. Logged a skate ski activity with 59,600' of gain in 1h40m. Not even running!

    3. Shows 968 feet of gain and 6h45m of running for the year, somehow is showing 8,919m climbed on the leaderboard. 

    4. Private profile. Might be legit.

    5. Logged a 2 mile run with 35,942' (6.8 vertical miles) of gain.

    6. Probably legit.

    7. Probably legit.

    8. Is literally the dog owned by #7

    9. Probably legit.

    10. Probably legit.

    11. Probably legit.

    12. Probably legit.

    13. Me! 

     

     

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  • A friend of mine had a KOM on a short hill climb (run) in Los Angeles, and was notified when somebody broke it. We calculated the pace of the new KOM to be that of a 1:12 Mile! We then clicked on the route that the guy "ran" that day. Turns out he started in Avalon, on Catalina Island, and ended in Bakersfield. This was a total distance of over 150 miles, done in less than two hours. Conclusion: the dude was in an airplane...!

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  • This is a real bugbear of mine. I'm currently in a total distance virtual ultra challenge, with actual prizes at stake. I'm busting a gut to keep up with somebody who is posting running activities on a daily basis which are simply not possible. This person has GPS data so bad that they are being credited with multiple kilometre splits of under 2 minutes, including one with the astounding time of 1 minute and 10 seconds. That's like run 100 metres in 7 seconds and then repeating the feat nine more times consecutively. Eat your heart out Usain Bolt. The world best for running 1 kilometre is 2 minutes 11 seconds. Surely it can't be too difficult a task for Strava to flag up and disqualify such obviously  impossible times?

     

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  • I agree. It really messes up some of the best climbing segments in my area, also cycling segments. I hate that, please fix it!

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  • This would really help on both rides and runs. I just flagged someone who did a ride with an average of 41kph. This itself isn't too strange, but when this person never rides at this pace (averages half of it), regularly rides above 50kph in the specific ride and tops above 70kph on a segment going uphill, something is wrong.

    Strava automatically shows time and distance data on a users profile, so an average can be calculated. When a user performs a certain amount better than this average, automatically flag the activity. Or even better: show a message: "There seems to be something wrong with your activity", then show the edit-activity window.

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  • I agree 1000%

    The results of the monthly running climbing challenges have absolutely no sense at all.

    To solve this matter, Strava should have a basic filter when uploading the activities. Those not responding to the "human parameters" should not be taking in consideration for the rankings.

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  • Here’s a good example of Strava’s automatic flagging hard at work:

    https://www.strava.com/activities/259789356/segments/60032954846

    This segment is part of a 5k that’s run on an airport runway, but people evidently start Strava while on an actual airplane. Strava happily obliges, granting them a course record for “running” at a casual pace of 33s/mi.

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  • Elle, your auto flag feature is broken and nearly useless. For example, check out this activity.

    https://www.strava.com/activities/675004572/analysis 

    Could you please explain why it failed to flag a ride when part of it was done at 75mph on a freeway? Your developers haven't made any useful improvements in years and are wasting their time on nonsense fluff that premium users don't even care about. I want to like Strava but as it stands I won't be renewing my premium membership.

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  • Elle, you say that there is an automatic system to flag rides, then explain this:

    https://www.strava.com/activities/1219315349

    I can send more, but, I can't go over and find all those rides... I see it all the time

     

     

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  • There are several types of activity auto flags that could be working.

    1- Compare segments/totals time, pace, speed ... etc, with type standards.

    2- Is the user breaking any WR?

    3- Is the user running/biking over water?

    4- Is the activity type odd to the same type while in Group Activity?

    5- Is the activity type matching the user speed, pace, time ... etc?

    And lots of possible matrices to correct or flag types, ensuring real data at segments and other statistics.

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  • Yes, what Chica said.

    It's even more annoying when if one flags, the message is that it has already been resolved.  For example, when flagging a zwift ride where a rider from Korea allegedly averaged 700 watts for 40 minutes.  Not only did strava not flag that automatically, but you apparently disregard subsequent flags on that activity.  Or the recent ones I've seen with guys using strava on motorcycle trail rides.  Your automatica flag doesn't note when a rider does 3 to 4 times the distance and vert that a cyclist could do in the same time?  

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  • I agree with everyone. Here is another good example:

    https://www.strava.com/activities/1281797177

    20km elevation gain on a 21km run next to a lake. The elevation data is obviously broken. I flagged the run, as Strava didn't. Runs like these make the Elevation Challenge pretty much useless for those who compete for the top position.

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  • This auto-flag feature is clearly not working, and because you're comparing to other athletes times then it won't ever work when loads of people are riding in vehicles or on motorised bikes. The problem is getting bigger the more people use eBikes/eMountain Bikes are for some weird reason like to leave the GPS on and then claim loads of KOMs.

    For example, there is a downhill mountain bike path here where I live, at the bottom a van picks them up and drives them back to the top. They all leave GPS on, and the top 20-40 odd places on all the road climbs that are hit on the way back up are held my mountain bikers in a van. Result being they're never flagged.

    For cycling the solution is so simple the fact Strava hasn't implemented it makes me think they don't want to solve it.

    You auto calculate a wattage of users without a PM so why are you not using that? If the calculated w/kg is more than a pro can do - auto flag the ride, they're in a car or they have a motor.

    If they have a PM and the watts are tiny but the VAM is massive, flag it - they almost certainly have an eBike.

    One of the biggest reasons for using Strava (for me) is the motivation going for segments gives me to get out riding and training. If the system is broken in favour of people 'cheating', what's the point in continuing to use it?

     

    Same for running (I don't run) - but stick a reference point of mile time based on the best pro athletes, and when amateurs smash through those trigger points, have the system flag the runs.... so basic.

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  • I only ride, never run.  But it seems my STRAVA account resets to "run" which then makes my rides get "flagged".  How can I set once and for all, BIKE, NOT  running?  Thank you.

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  • I'm wondering if the autoflagging system has changed recently, because I am losing CRs to cyclists almost every day now, whereas it used to be a once-a-month thing. Many of these activities have multiple mile splits well under 4-minutes, half marathons under 59 minutes, etc.

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  • The autoflagging system is definitely not working. I get messages every single day because I have KOMs on a climb that is often used by mountain bikers doing laps and using their cars to drive up before cycling downhill on trails. They are doing the climb way faster than the 25-50% rule mentioned by Elle above (often 200-400% faster). Come on Strava, people have been complaining about this for years. It seems like a very easy fix. Just implement the rule that Elle describes, and make sure it actually works. The leaderboards are meaningless if they are full of people using cars and motorbikes, and it is incredibly annoying to have to flag these ridiculous "rides" every day.

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  • A month ago I had flagged a ride where no time measurement was recorded, only the distance. It was a KOM party for that rider, with unbeatable 0 s in every segment. I conclude, there isn't any automatic.

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  • please can someone review the following ride, I cannot flag them because they say they are resolved, even when they have photos posted of their motorbikes during the ride

    https://www.strava.com/activities/1437372773#35760856993

    https://www.strava.com/activities/1515456777#37808747573

    https://www.strava.com/activities/1290013251#31889347407

    then top 15 in this segment are all on scooters/motorbikes and cars... https://www.strava.com/segments/8734553?filter=overall

    it is ridiculous, the autoflag is not working on this segment..

     

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  • The auto flag system is still a total failure.

    https://www.strava.com/activities/441965873/analysis

    Someone was supposedly biking on a freeway at 65mph! How come that wasn't caught?

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  • The algorithm for auto-flagging makes sense for detecting new suspicious activities, but there are some segment leaderboards that are composed entirely of impossible activities, so the 25%/50% thing would not work:

    - Popular running/cycling locations where people park, ride or run, and then drive away. Frequently any segments that a car would exit the location have the entire leaderboard filled with people in their cars driving away. These activities are really obvious and I believe could be identified programmatically (e.g., if a run was at 9 min/mi pace and then suddenly is at 3-4 min/mile pace for multiple miles, that is impossible unless the person is in fact the fastest person in the world). It's a little tricker for identifying bikes vs cars because speeds can be similar, but usually you can tell if the ride ends in a different place than it started and goes on a highway :), or if it is going uphill at world record-breaking speeds.

    - MTB routes that involve shuttling to the top of a route, and biking downhill. There are loads of these segments where the entire leaderboard is full of activities that were in a van or in a car. This ruins road segments anywhere near popular MTB routes because you'd have to flag a bajillion people. These are also very obvious and I believe could be identified programmatically because you have MTB downhill segments followed by 40mph uphill shuttle rides. Any activity that has extended climbing speeds on a bike of 40 mph is suspect and it seems like that could be a way to improve the auto-flagging algorithm (e.g., min grade + min speed + min distance generates a flag if it exceeds bounds that would exceed current world records).

    - [Separate but related] One other thing that would be really cool is if Strava provided a recommendation for cropping the activity when it auto-flags. This would help empower people to know how to update their activities and keep the experience more positive.

     

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  • Dan, go to your Settings page and change your Default Sport.

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  • Over the years I have flagged literally 1000s of rides by motorbike riders.  Sadly Strava you are going to lose your supporters if you are too lazy to implement auto flag for obviously false rides/runs.  There are other apps out now that are very similar as well as Garmin.  I'm just sick of having to flag the same motorbike riders, with profile pics of their motos, for doing 100km/hr up a 4% slope.

    It's just lazy on your part Strava and I'm looking elsewhere now.

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  • As I post here last year, wonder if you have to flag in bike and run activities, like I do. And you find every day an senior heavy weight WR breaker!!!
    It’s not had to put under quarantine any activity that is faster than any WR, in 400m, 1km, 5..... even a marathon winner faster than the fastest Quenia runner.
    In the other hand, around here, the bike segments KOM are almost 100% in a semi tail! They had rode the activity, but 90km/h is not real and should be auto flagged to.

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  • This is ridiculous. some really simple measures could cut vehicle activities... like riding over 100km/h on anything but downhill. Or accelerating from 0 to 60 in a few seconds. Or climbing 10% hills at 50km/h. Lol... Anything that requires over 2500w should raise an alert as those numbers are only hit for a few seconds by top pro track sprinters. I refuse to pay premium while that kind of filter isn't added.

    PLUS there's no flag button in the android app, only in computer website.

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  • Why does Strava claim to have an autoflag system when it clearly doesn't or have one that remotely works? I was just on a training trip in Mexico and many cycling segment KOMs were listed being done at 50-80+ miles and hour... Here's one of many, at 50 mph on a zero percent grade:

    https://www.strava.com/segments/19847682

    For a data company, it seems astonishing Strava is incapable of implementing simple algorithms to flag data like this. Without a an autoflag system, I'm certainly not going to spend my time doing Strava's work reporting these. Why encourage people to create, train for, compete at segments when the data is invalid. It's very sloppy.

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  • Elle, I agree with Jeffrey - something must have happened because there is a person in my area that logs 'Drives' and regularly I need to 'Flag' their activities... pace of run... 45-60mph... :-/

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