The formula for getting any residency, in any specialty, is pretty universal...
1) Pass boards (and have required citizenship status for the program)
2) Have a good enough gpa to get the clerkship/interview
3) Read books, manuals, and journal articles - especially any by the attendings of that program
4) Do the clerkship and/or visit... work hard, show interest, get along well
5) Have a strong interview
Competitiveness varies too much to speculate. Your guess is as good as anyone's (besides maybe the program's director). There are programs that consistently get a ton of apps, but even "top" ones watch their interview app numbers wax and wane to from year to year. You also have to take into account that, occasionally, some spots are already decided based on nepotism or "connections." Overall residency spot competition surely depends on the ratio of applicants to entry level spots; a lot of spots that went unfilled in 2007 will be competitive in 2009 and beyone. As for one individual program's interest, it might come down to the amount of 4th year pods looking to move to that area, their recent recruiting efforts at fairs, if their current residents have advised a lot of underclassmen from their alma mater to do the clerkship, etc.
In line with your "purely hypothetical" thinking, OSU's program might get 35 interviewees for two spots and ten guys eventually deciding to rank them #1, which makes them very competitive in that cycle. The next year, the residency might publish a comparison study on a couple antiquated 1st met osteotomy techniques, and they might consequently scramble a spot... who knows? 😀 The only thing you could really do is ask students at pod schools near the program (ie OCPM and Scholl for Columbus program) how many of their classmates are clerking there. That is a general gauge of interest, but you still never really know how many of those students have serious interest and will actually apply for the interview versus those who just clerk there to learn for a month and are more keyed in on other programs/locations.
