CS told me a few months back that there is no 4 season window at D2 and D3, the 4 year window is only for D1. So basically at D2/D3 you have a # that is your prestige and that gets changed into a letter grade that we see for prestige. And depending how your season guys it's weighed into that number. So say you an A+ rating is 800+ and you have a season that is rated only 700 it would likely drop your prestige at D2/D3 since your previous 3 seasons aren't directly factored.