First thing that came to my mind was what is considered quality code. Here is an excerpt on how they filtered high quality git repos from Github based on number of stars:
> However, one can assume that repositories which are of interest to people and are more widely used at least exhibit a decent level of code quality. The 4 star boundary was chosen arbitrarily. The rationale behind that was only based on the assumption that repositories are most likely pareto distributed according to stars and quality, meaning that even excluding repositories with only a small amount of stars will exclude most GitHub repositories and yield more high-quality repositories.
Edit: added a missing word