Roundup scores are calculated as follows. First, each game is given one of the following ratings with the corresponding amount of points:

Avoid It (0 points)

Skip It (1 points)

Check It (2 points)

Try It (3 points)

Play It (7 points)

Love It (10 points)

Games that could not be played properly are not given a rating, but they are made note of in case this changes in the future. Next, the score for the episode is calculated like this:

total points / (amount of games * 5 - omitted games * 5) * 100
As you can probably tell, in a theoretical situation where every game is a "Play It" or "Love It", this would result in a score above 100%. However, there is a reason for this.

Originally, only "Skip It" (0 points), "Try It" (3 points) and "Play It" (5 points) existed. However, the resulting scores did not reflect my actual feelings on the batch of games well. It also doesn't make sense to consider a scenario where every game is a definite recommendation as 100%, as this will never happen in practice, and it's somewhat useless to judge a batch in this way; nobody is actually going to want or need every single game to be amazing, and docking points just because some incompetent assholes happened to release a piece of crap in the same time period as a bunch of good games just isn't fair.

Because of that, the rating system has been gradually refined into what you see above. The more granular ratings allow me to better indicate my feelings, while the boosted numbers create a better-looking final score that doesn't give the impression that I hate the entire NES library or something.