I talked recently about the H/HP/P/LP/F system at my medical school. In our anatomy class, you needed 85 for honors and below 65 was failing.
If you got a 84 or a 64 average, you were allowed to ask for a regrade. The anatomy professor would go through your two midterms and the final exam in order to look for extra points to boost you to either a passing grade or an honors grade.
I always thought my anatomy professor said some really wise things, and this was what he said on the topic of regrades:
"I've found that students who got a 64 don't have a very good grasp of the material, so usually we aren't able to find enough places to give extra points on the exam to help them to pass. But students who got an 84 usually have an excellent grasp of the material and usually there are ample opportunities to give extra points on the exams."
Lucky me, I had an 82.