I had a friend who had a private box at a horse track. One of the benefits of this box was that you had a personal betting machine. This let you bet on the best odds just seconds before the race every time. I made a lot of money doing that.
You can kind of do it in Vegas too because the sports books aren't usually that busy.
In fact, that hardest part of this strategy is actually figuring out who the favorite is! The odds are usually listed as fractions, but they have different denominators, so you quickly have to convert them all the the LCD and then order them.
But yes, the closer you bet to post time, the better your outcome with this strategy will be.