FPS based on the median of a moving window is good if you want perceived frame rate, which rejects extreme outliers.
FPS based on the average of a moving window is good if you want statistical mean frame rate.
This.
The other two are not good for anything gaming as any framerate inconsistency breaks the experience. A stable frame rate is much more important than a high one.
Considering stability is the name of the game:
1. If it’s changing quickly in the ones position because it’s not stable, that’s immediately apparent
2. If it’s changing quickly in the significant digits, specifically hundreds or tens position, that’s immediately apparent
Which is largely all the info a user cares about anyways. It gives them the three important states:
1. Stable
2. Mildly unstable
3. Severely unstable
That is, if the number is entirely unreadable with this strategy, it’s because the game is entirely unplayable.