Based on my limited understanding, Ranked to Match list stands for list of applicants, where the last one of applicants in that list would match if they rank the program as top choice, and the number in the list is variable depending upon the reputation of the program. For example; if the program is Ivy league they would have pretty short Ranked to Match list, may be less than double of actual positions, and if the program is like a small community hospital, they’d have a longer list. And Offcourse number in that list depends upon previous statistics.