@bclintonk Obvious not everyone has a 50% chance. Nowhere I assume that. I am responding to the one who said would apply only if one certainly would get it. If one is certain to get in, it would be 100% admission chance. I am just saying those almost certainly would not get in should not apply. A B+ student that you referred to with uwGPA 3.3 would be under that category as admission average GPA is 3.85. Same for students with ACT below 26. That is the self-selection process. Those in the grey area (i.e. slightly below 25th percentile) from in state should definitely try even they are not certain to get in.
At my D’s school, over half of the 400+ graduating class apply to UMich every year and around 100-150 get admitted each year.