User blog comment:Plexioth- xD/Monster Hunter 3 Ultimate/@comment-184.38.31.72-20111230181118/@comment-3062343-20111231224843

I think Deviljho231 was mixing up "evading" (referring to using MOI to roll through the attacks) with "avoiding" (simply getting out of the way of attacks). In general, the faster an attack, the easier it is to MOI through, but the harder it is to avoid. The hitbox sizes are also obviously a factor in the difficulty to MOI through attacks, which is why Nargacuga's tail swipes are, in my opinion, the easiest attacks to roll through (fast + small hitbox = easy to MOI).