The VA lawyer told me its based off ROM. In his words...the incapacitating episodes is holdover from a time (decades ago) when doctors used to prescribe bed rest during recovery from back injuries because they thought it was necessary. However, that's not really the case anymore. He hasn't seen anyone get rated based on incapacitating episodes, and he's seen a lot. As far as percentages, he'd seen two get 40, one get 60...and the guy that got 60 was in really bad shape (quote "you would not want to be that guy"). Most are 10-20, like 95%. It's really hard to get higher from what he explained.