There's a formula I use for Viewership Score which basically accounts for a best guess of what the average "would be" if all the games were televised

First I take the harmonic mean of the average rated game and the median rated game (to help reduce impact of huge outlier games where they get a big number against a marquee opponent)

Then I take the harmonic of that number and their overall average (with zeros for all their non-rated games). Basically it's trying to bridge the gap between giving them no credit for those games and assuming that they'd do as well as they did in their other games.

Because it's a harmonic mean, the larger the difference is (or the more games they don't have aired) the more their result will suffer