Better to do 2 rotations. Statistically chances of matching are lower with 1 or 3 or 4 rotations.
If you don't mind me asking - is there data to support this or is it just hearsay? I'm curious because at my school (where there isn't an ortho program), its common for people to do 3 aways (the max our school will let us do). I've got a strong app, and really only want to do 2 aways; but I've been leaning towards 3 since 1) I can, and 2) more aways can only help, right?!
Here is a link to a study from 2009]
http://www.ncbi.nlm.nih.gov/pmc/article ... ool=pubmed[/url].
Although the results of the study do show that doing 2 aways has statistically higher match rates, 3 aways is not far behind at all. The study also went on to break down the type of applicant who does 2 versus 3 or more aways, showing that the typical applicant doing 3 aways is a weaker applicant.
So as far as I can tell, if you are a strong applicant (Scores, grades, LORs, research, etc), doing 3 aways should only HELP you. The 3rd away would most likely be late enough in the year that ERAS +/- Dean's Letter already went out, so it should only help/hurt you at that specific 3rd program (i.e. you won't be counting on the LOR from a 3rd away to improving your app to all other programs).
However, this is a bit different if you do not plan to or have the option to rotate at your home program before going on aways. If I were you I'd definitely do 3 aways.