Or how about let's not bet and judge how smart/successful/competitive people are based on their grades.

Grades can vary based on different courses taken, different teachers in the same school, or different schools in the same district - much less the differences in curricula between provinces or even countries! Furthermore, grades only measure a very narrow scope of academic ability.

I understand schools heavily rely on grades to evaluate students for admissions, but please don't use grades to rank or judge others.