Taking a Big Favorite down a lot of points 2nd Half Strategy

I don't have a spreadsheet.  But I've lost my shirt  following your exact philosophy - taking big favorites down @ halftime to win the game.  Especially on the road. But even @ home as well.

My theory on halftime bets are that oddsmakers have competing interests. 

First, they try to be consistent w/ the FG odds.  They know a lot of bettors don't like the 1H results and are nervous about their FG chances.  So, by putting out a line that matches the FG, they know they'll get free money.

But obviously in many games, it's impossible to do that. The favorite is losing. Or the dog is losing by more than the FG spread.  Often, I notice the spread for 2H is one-half the FG spread.

Then there's everything else. The 12 pt fav is getting crushed by 9 to the dog. etc, etc.  In these situations, I'll see the spread for 2H to be enough for the FAV to win the game. 

 In a 10 minute window, it's impossible to ensure even betting.  Or anything close.  So, my theory is they set the proverbial trap.  They pick a number to entice bettors - or at least the public - to bet on the wrong side of a bad line.  It's my theory and I'm sticking w/ it.

So to the OP's reasoning.  My theory is that's probably conventional wisdom. Most people would think that the better team will come back and win b/c, well, they're a big favorite for a reason.

So, ask yourself: why is Vegas setting the line so the fav just has to win?  And, just who exactly is betting that the dog will win outright?  

If big favorites came back and won most of the time, then guess what - Vegas would move the line so the fav has to win big in order to cover the 2H bet.  But they don't.

OTOH, here's why I bet Milwaukee -9 for 2H pretty hard.  Milwaukee was a -7.5 favorite.  Now they're a -9 pt favorite JUST FOR THE 2H.   The 2H line is greater than the FG line????? And Milw  isn't a popular team.  So it seemed like Vegas wanted to attract PHX bettors. 

So that was my theory. I have no data to back it up. It worked in the PHX/Milw game, but maybe I just got lucky. 

If anyone does have data for 2H bets, please share. I'd love to see it as well.