Uber Nairobi Ambulance Perambulation Challenge
$6,000 USD
Can you use ML to create an optimised ambulance deployment strategy in Nairobi?
1029 data scientists enrolled, 331 on the leaderboard
17 September 2020—24 January 2021
130 days
Unexpected Behaviour of Submission Scoring
published 22 Jan 2021, 11:02

Hi everyone,

during my recent set of submissions I encountered some unexpected scoring results. Basically, I first submitted a solution that had the same ambulance locations for all dates and times - let's call them "base" locations. Then, I went on to change the locations based on to which day of the week a specific date in the submission corresponds (Monday, Tuesday, ...). I did this for each weekday individually so I ended up with 7 different additional submissions, one for each day of the week where the locations for dates corresponding to that weekday had been changed but all other entries where still the "base" locations.

Now, here comes the (to me) surprising part: All of the submissions gave me the same result, except for the Tuesday submission. I am wondering how it can be that 6 out of 7 times I changed 1/7th of the submission (slightly as the locations don't move a lot, but still, they are different) and the score stayed exactly the same.

Does anyone have an idea what is happening or maybe experienced something similar? Any help, hint or comment is appreciated.

Best of luck to all participants in the final days!

I had this issue yesterday, thought it was a bug in my code (Maybe it was ). But seems to be fine now ..Try the submissions again

Thanks for the reply! Good to know I wasn't the only one. I will try again once my quota is restored ;)

Hi, i think only tuesday, wednesday and thursday are in the test-set for the public leaderboard. The other days have no impact on the submissions.

I'll suggest you check your code, From my experience over here.

It's most likely all days are in the test set

Hi Balogun, thankyou for your reply. I checked a submission wich has score 41.01.... Friday to monday i set all six ambulances at -2, 38. So i would expect a much higher score if theese days are involved.

Hello, I can now confirm that Sundays are definitely in the test set ..

I'll suggest you read_csv your submission file and make certain your locations for each day are in fact reflected in your submission.

Hopefully that helps

Hi, thanks agein for your reply.

Its realy puzzling... thats waht i did, reading the file into Excel, and filtering on the date. If you ar interestetd, you can see it here:


Yes. you're right ...

There was a bug in my code all along

thankyou for this reply again

Please which approach can I use to improve my score, I tried KMeans it go me to top 120

There's a starter notebook that implemented gradient descent in the discussion forum, you should give it a try