Board Thread:Versus Debates/@comment-34656247-20180726110937/@comment-26107879-20180727213617

Actually. Hiruzen was known as the professor for his mastery of all forms of Shinobi combat and knowing and being able to use every jutsu in Konohagakure.

Hiruzen was renowned as The Professor (プロフェッサー, Purofessā) due to his mastery of all forms of shinobi combat,[6] reputed for having advanced knowledge and/or skill of all the techniques to ever exist within Konoha, including the many Hiden techniques.[33][4] chp 94, 120, 4th databook.