From my personal experience in the scramble.
If your chairman told you that you shouldn't rank any intern or transitional years at the end of your rank list, b/c if you didn't match you would need to go to a top school prelim year in order to get into a program if the scramble didn't work out:
{I had four papers (one 1st author, two Rad Onc red journal articles none of them 1st author) and five radiology abstracts}. Don't Buy it!!! After no matching, I didn't have a prelim or transitional after interviewing at 10 programs b/c I took questionable advice. Two of my friends failed to match in derm for the 2nd time one did a prelim, another did a transitional both missed.
I didn't know any better and couldn't get the Stanford, Mayo Clinic, UPenn pre-lim IM programs to call me and when I got a prelim IM at a satellite hospital of my home program {where I didn't interview} I was told not to accept it by my Chairman. He had no idea what he was talking about! My Boards were in the 220's, not enough for the big names of the very few that had open spots {Duke and their short white coats}.
I met a guy at two of my interviews who was in a surgery prelim program at a small program in Florida--not at all useful in my mind for Rad Onc, but still he was considered a valid applicant, though I have no idea what happened to him. I often hear from residents and an occasional attending that many residents who did a transitional year had no idea how to manage a medical oncology emergency..I always thought this was nonsense. Many foreign medical students are equal if not more passionate/competent/harder workers than my former classmates. If you're a good candidate no one will care what intern year you went to.