I'm not sure, exactly. It could be that they were simply older than other runs, even by a small margin. It could also be that ILs don't show up on the FP. Or they could have some way to determine game popularity thought I highly doubt that last option.

There aren't any other options other than a button to verify. I just looked again under editing the game and it doesn't look like anything there would do it. If you're burning for an answer, you can try asking on the general forums.