Both. You need to have a sense of how competitive each program is and whether they have preference for instate residents (for the public unis) etc.
I am not an expert on this. I just happen to know a few friends kids who were not successful because they underestimated the competition and did not research the admission rates for these programs. They also incorrectly perceived that the 7year programs at the less "prestigious " instate unis would be easy to get into. These programs put out a lot of information about the process with stats,and yet applicants harbor some sort of magical thinking .