Reputation can be used as a weight in a model. Since we expect that a larger reputation means more HP stacked! It is something to think how to add that. Like other people said before, time can be a weight as well. How old an account is? Since we see many high-rep accounts and very old accounts... we are transforming it in a linear model , if you are curious about it:
https://en.wikipedia.org/wiki/General_linear_model
It is an interesting game just need to have time to play with it!