A person winning a contest 15 times out of 17 seems really concerning, but it's good you've done your research, I think for one, the constant winner will have to stop being the winner all the time. It's going to be sad if truly someone is creating multiple accounts to game the system.
I think for one, the constant winner will have to stop being the winner all the time.
Here the even bigger problem is that the creator of the contest and the most frequent winner seem to be the same person, and so in this case it would be a contest created to farm with no or very little risk.
I think it is only fair to wait for gladiadorr's response although I don't know if it will come