• What are the numbers in gray?

On some views of the site, there are numbers in gray ovals.

For example, when looking at a user's completed tasks: http://www.checkio.org/profile/user/stamparm/vs/Albin/

On some assignments which both users have sold, this gray number differs. It appears to be some sort of "score" (Higher for published solutions, Higher for liked published solutions, Higher for tougher tasks?).

What is the system?