Sacchi won two European Cups and a Serie A title with AC Milan back in the late 1980s, but Pirlo feels that Juve's current boss is an even better manager than his Italian compatriot.
"If Arrigo Sacchi was a genius, then what is [Conte]?" Pirlo wrote in his autobiography.
"I was expecting a good coach, but not that good. I thought [he was] a coach with a lot of grit and charisma, instead I discovered that tactically and technically he has a lot to teach many of his colleagues.
"I am extremely lucky that I met Antonio Conte. I had so many coaches to compare him to, and he is the one who surprised me the most."
Juventus are currently top of Serie A, nine points ahead of Napoli in second place.