The wrestlers who out performed their seed by at least 10 spots is heavy in the past 4 years when everyone was seeded, but here is that list anyway. There are also a few from the 16 seed era on the list.
Killian Cardinale is clearly the most under rated wrestler of all time.
In the 12 seed era (1979 - 2013) only one wrestler outperformed his seed by double digits. Edinboro's Jarrod King won 165 as the 12 seed in 2009.
Also in the 12 seed era unseeded wrestlers made the final 9 times, winning twice.