The Vegas odds of Romo starting a game for the Cowboys this season went from 2/1 two weeks ago to now 65/1.
Wow that is really strange, Vegas is not in the habit of offering huge long shots unless they are severely undercutting the price, meaning if the true odds of event "A" occurring are 200:1, then vegas will only offer it at 150:1 and probably limit the max bet.
They arrive at this figure by taking the number of games left, the chance Dak wins the job, other factors and perhaps some inside info not presently revealed to Joe Fan. If somehow Vegas knows Romo won't start again, its right in line with Vegas' habit of severely short changing the bettor, as 65:1 odds are awfully enticing but no risk to Vegas if they already know Romo is done.
On the other hand, the line change in a typical game indicates vegas is trying to get money equally distributed on both sides, not necessarily that an events outcome is more or less likely to occur.
I'm not sure if odds bets like whether Romo will start work like typical games, but if they do, then it means Vegas already has a lot of action betting Romo won't start again, Vegas knows he wont start again, so the book is offering 65:1 to get people to bet that he will start, which would make sense given the way the line is moving.
If I've done the math right, it sounds like we'll soon get an announcement about Romo being out for the year.