I was just curious if anyone had any stats on how often programs offer PGY2 positions or categorical positions to their non-designated preliminary interns. I will be doing a year at a very well known, research oriented program and while I am prepared to look elsewhere for a PGY2 spot or even match and repeat intern year, I was wondering what the chances of this best case scenario were.
No statistics are actually going to be of much use for you. If your program has an open categorical slot and they want you to fill it, then you will get it. Some places have openings (as people in categorical slots will elect to leave) and sometimes you hit a year where everyone stays and you won't have a slot.
If you are interested in getting a categorical slot, you need to be pro-active and speak with your Program Director right from the start. Your Program Director isn't going to ask you about your plans, you need to initiate this conversation and ask their specific advice for your situation. This person isn't going to come to you and ask you if you want to stay so you have get as much information as you can gather from Day 1 to put yourself in a good position to get a slot should one become open. First, do an outstanding job with patient care and hone your surgical skills to the highest level possible; do well on your tests (ABSITE) and last, make good connections with the teaching faculty so that they are supportive when it comes to your evaluations.
The good thing is that many programs will take a "known entity" over an unknown "entity" if an opening becomes available. The worst case scenario is if you do the above is that your program doesn't have a slot and you go elsewhere with very strong letters. It's also a good idea for you to have your application materials ready to go so that you can enter the MATCH next year, apply early and get some solid interviews. I would plan on going back into the match in any case and hope for the best i.e. you won't have to.
Most PDs know in February if there will be open slots for the next year(they have enough evals on the current residents) and will let you know if you have a shot. This is why you can't "hang back" and hope but why you need to get out there and do everything possible to get a position. Start early and do your best to outperform in every area that you can.
If there isn't a slot, I wouldn't stay another prelim year waiting for one. If you are not going to have a categorical slot after your PGY-1 year, enter the MATCH and repeat your PGY-1 year as a categorical at your new program. I wouldn't waste a second year of funding in a prelim position as it becomes more difficult to get into a categorical slot at an outside program after two prelim years.