It's not a secret. By substituting freely from the beginning of the season, you may take some hits to your record, but come February and March, you have a team of 9-10 guys who have all seen regular minutes. They're all used to playing with different combinations of players so there isn't as much of a drop-off in team play when you rotate players later in the season. Everyone has real minutes and has gained valuable experience in "real" games. It's not a coincidence to me that JB's teams typically have a February swoon.
There is also less of a drop-off from year to year because no one is starting from scratch as a sophomore since they all log minutes against legit competition.
Listen, I love JB and everything he's done for SU, but I have always bemoaned his lack of bench usage. His response is always along the lines of, "you can only play 5 guys at a time, so it only makes sense to play your best 5". But, I am a firm believer that your best 5 can be better at the end of a game and season if they are occasionally subbed out. It also acts as a mitigant to losing a player to injury or academics in March (hmm, where have we seen that?).