[dwrodri]

I think if you take "grit" to mean "discipline", it goes a long way.

In my opinion, it's better think of school grades as a measure of efficacy instead of intelligence. Given a fixed amount of time, how correctly could you perform the task? Discipline, or "grit" as it has been called earlier in the thread, refers to one's propensity to allocate larger portions of time towards accomplishing a single task, especially in the face of adversity.

Hopefully this perspective makes it more clear how "grit" is useful.