I've noticed something strange about the Critical Block percentage calculation at Level 120. While it goes up as normal from 130 rating to 332 rating (1% to 33%), it completely stops for about 32-33 rating until 364-365. Usually this would net you around +5% at any other rating, but not at this strange dead-zone.
This wasn't present at Level 110 and it seems too odd to be intentional. It could also explain why block decays such an extreme amount compared to 100 > 110.