Ben only lists 1 three year sample for jordan
Jordan's average from 89-91 is +7.7 in backpicks bpm and +7 in aupm, averaging to +7.35
For Lebron Ben lists three different three year samples(08-10, 12-14, 15-17) in AUPM:
08-10:+6.8, 16-18:+6.7, 12-14:+5.1
He only lists 12-14 for both bpm and aupm:
12-14: +5.8
So if we just use his three year averages, we see that lebron has a bunch of three-year stretches close to MJ but MJ's 89-91 scores highest. However it's interesting that lebron has three 3 year stretches that rank so high(2nd, 3rd, and 7th) and the lowest score came from the years ben rated as Lebron's peak. If we take a look at lebron's best two years from each of those three year stretches...(aupm/bpm is averaged)
Lebron's 09, 10, 12, 13, 16 and 17 are at +10, +8, +7.5, +7, +7.5, and +7.7 respectively.
You get 5 different seasons which would all boost the average of MJ's 89-91 peak.
14, 18, and 08 are all low points impact wise which prevent lebron from matching jordan statistically in this metric over three consecutive years even though he seems to comfortably have the best individual years by this stat. So i guess that opens a philosophical question of whether it's more important to string your best years in a row or to generally have better years when evaluating peaks.