There's no way the Dolphins have a 50-1 shot at the superbowl. They couldn't win last year with the QB they grasped at and they can't win this year with the QB they've grasped at. For perspective Trent Green is the same age Vinny was when he stopped being able to win anything. Green was having serious problems last year before he went down and didn't win much after he came back either.
The only odds that actually mean anything are the lines that the professional books offer. Those are the ones that are influenced by actual betting and as a group bettors are much more accurate than any other prognostication method. Every once in a while the masses are really wrong, like with the Rams in 1999 who were 200-1 against in most books, however generally the winner is a team with odds at 12-1 or less.
For perspective, Mandalay Bay's opening line for the Jets to win the Superbowl was 125/1, and that narrowed to a predraft 75/1. I didn't see where they were by the start of camp.