My local fast-food chain has trouble filling spots and is therefore lower-tier.
Seriously, as for Ortho programs, you'd be rather arrogant to class a program as "lower-tier". I have several exceptionally-smart friends who were unable to secure a matched spot and so this tells me that there is NO reliable "back-up program". Moreover, I rotated at a couple of lesser-name spots which had unreal OITE scores and operative experience. So, in general, the best strategy is to apply broadly and take as many interviews as you think reasonable. Then, determine your list based on your fit with the guys/girls/staff therein.
With that said, many departments are regional (think football conferences) and tend to preference within their conference... therefore *your* best shot at back-up places might be among those closest to you. Don't assume that a random program in a different time zone will say, "oh wow, you're 3rd in your class of 300 in Abigstate; we'd love to have you". Again, rotate and apply broadly and get a feel of the types of places where you'd fit well.
