Alright, maybe I'm coming down too hard.
Look, I'll just take you to the beginning, and leave it there.
If you didn't buy a ticket at that line, or know somebody who did that got paid there, then you don't even know if it traded there.
But even if it did trade there, it was likely run up. There were clients who wanted the favorite and likely paid a heavy spread price for it.
Are you understanding it yet? Are you getting it?
THE BOOK MAY HAVE BEEN RESPONDING TO ACTION THEY WERE WILLING TO TAKE.
Read the all caps sentence again. Now if you think the action they were willing to take, not all, just what I am referring to, is action on the dog, then you need to rethink what happened here. After all, the books are responding to action that they were willing to take in. That response was a rise in the favorite's spread.
That means, before responding, they had to take action on the favorite. Right?
Something had to stop the rise in the line. That would be a bet on the dog. A bet you seem to think will break the bank because, for some reason, you want to ignore all the bets that led that line to rise.
Strange, but your behavior is born out of ignorance to what the point spread is for, and thus why it might move.