In reply to: Very few go into Med school match without already knowing posted by OldIrishFan
I'm under the impression that it's an iterative process. In that case the person ranked higher by the residency gets the spot unless their first choice takes them also.
It actually works really well. As for surprises, that depends on specialty and applicant.
If a program A ranks applicant 1 first and applicant 2 second
And program B ranks applicant 2 first and applicant 1 second
And if applicant 1 ranks program B first, and applicant 2 ranks program A first
Then, applicant 1 will match to program B and applicant 2 will match to program A assuming there are no others where the applicant ranked the program number one and the program ranked the applicant number one
But that's a different case. Each applicant gets their highest rated residency that is available to them, but that doesn't mean an applicant can jump someone by having the residency listed first and sometime else using it listed at 5th.
In short, there's no penalty to listing "reach" residencies. It's hard to explain this, but effectively they run an iterative process so the residency gets the highest listed residents who have that residency as their highest listed available residency.