I didn't mean that the probability, from the start, was 25% for it to be selected in positions 49-52. I was (perhaps incorrectly) considering the probability after 48 cards have been drawn (believing that 1 of each suit would likely remain). You are just as likely to have drawn 'n' amount of hearts as 'n' amount of the other suits in 4*n draws. Therefore after 48 cards are drawn, you are most likely to have 12 hearts, 12 clubs, 12 spades, and 12 diamonds, no?
I do not believe that you can dissect which position the 13th heart is the most likely to occur in. Instead, I believe that it would only be possible to determine the GROUP of cards it most likely appears in--and my conclusion is that it is most likely to occur in the group that consists of positions 49,50,51,52.