In the case of LeBron, he had some seasons where he was first team all defense, which means your rating is at least 90. Once, you do that, even if you don’t make an all defense team, they will give you a 70 rating. This is why LeBron has a bunch of 90s, an 80 (2nd team all defense) and a bunch of 70s. In the case of Magic, his defense is based on his position and some formula they use that involves blocks and steals. That is why his defensive numbers are scattered all over the place, they were determined by his blocks and steals. You will also see players like Joel Embiid, who had some second team all defense seasons, which earned him an 80 rating, and some 60 rated seasons, which is what you get once you achieve that 80 level. Players will be 90s and 70s (Jerry West, DeAndre Jordan) or 80s and 60s (Joel Embiid, Al Horford) or scattered all over the place based on their blocks and steals and also incorporating the position they play. Also, the DPOY will earn a 100 defensive rating. If someone has anything to add, or if I’m wrong in any way, feel free to chime in.