Board Thread:Naruto Discussions/@comment-995176-20161122010151/@comment-9782468-20161122031923

Chuunins are not only promote based on their combat capabilities, they're promoted on their ability to lead a team or follow their leader well. Basically how well do they function with others, and how well they can think critically about their abilities and the abilites of their teammates. Chuunins lead missions, after all.

Also, Naruto had to study for years to get Jonin (if he ever even made Jonin)