^as above. If we assume that the applicant score is at the mean for that specialty, And you interview well and have good personal skills, you’ll need to go on less interviews if you want to get into Lesser competitive programs. Traditionally, the rough average has been about ranking 10 programs which will give you a very solid or over 90% chance of matching into that field. Meaning ideally you should go out no less than 10 interviews, and have flexibility if you do not want to rank every program you visit.
Every year they put out the match data which will show you what your odds are for the number of interviews in the field. Go to the NRMP and spend some time looking over those.