...F2 winners average 68% of the vote.
...F3 winners average 48% of the vote.
There have been
ZERO times have the F3s had a no vote finalist. Froslass got 1 (14% of the vote), Garen got 1 (12% of the vote), Azmodan/Tracer both got 2 (28% of the vote), Dan got 1 (11% of the vote), and Theodora got 1 (10% of the vote).
The average difference between 1st & 2nd in terms of vote % across all games was 28.89%.
Broken down into F3 vs F2, F2s had a 35.15% difference on average, while F3s had an 11.36% average.
Also, for fun, I analyzed jury sizes:
Here's the link if you want to see the data.
Some takeaways: wow, we have had way less F3s than I thought.
F3s are far and away more competitive than F2s in the site's history.