On the academic side, it was just a couple per year, but there were other red-flag situations that got waved through too (behavioral). It all added up to a bunch of risk-taking that rarely paid off.
There's some academic things that are fixable (kid needs to take a remedial math course) and there are some things that were unfixable (kid fails to qualify on GPA and/or SAT).
Back in the 1980s, I tutored a well-known starter-level football player who had to take a remedial high school Algebra II course before he could enroll for Business Calculus. He did well, graduated from UM, has a successful life now. I'm glad we took the risk and I'm glad it paid off.