When do we get negative rating?

codechef
ratings

#1

In march long challenge, I made one successfully submission and still my rating for that contest was -1116
how this could be possile.


#2

Your rating decreased by a large value to make it negative because your performance was below expectation.

Initially a new user is given 1000 rating and in the first contest if he/she does not perform well compared to what is expected from a user having 1000 rating, then the rating will decrease, otherwise it will increase.

You can find some details about this rating system here, here and here.


#3

Your rating is also dropped if you are caught using false practice. More about false practise
here.