The Dog and Over is a "system" play, and not an "opinion", meaning I play it regardless of who the teams are or any "analysis" of outcome. Pretty much. It rarely applies in NFL, but almost always in NCAA games. Starts by finding a game where the SPREAD gets close to the TOTAL. When that happens, you play 2 separate plays: The Underdog and Over the game total.
The decision: Take the game total and subtract the spread. Then divide by 2. Ask yourself, can the underdog score that number? If yes, you can't got 0-2, you will be 1-1 or 2-0. Before you say, "what's so great about going 1-1, I lose $?".....keep reading.
Example in last weeks Michigan -38/47 game vs Rutgers. 47-38=9 then divide by 2=4.5. Can Rutgers score 4.5 points? If so, you can't go 0-2. If they get just 6 points, to cover the -38 Mich has to push the Total "over" (44-6). So 4.5 points by Rutgers gets you at least one win, and maybe both. Can you lose twice? Yes. But it takes a Rutgers 0 and Mich exactly 39 to 46, or Rutgers gets FG it takes 42-3 to 45-3. That's 11 possible scores out of the hundreds or possible outcomes. (OK, I'm leaving out safety games where they could score 2 or 4 points!) The window to go 0-2, while possible, is very hard to hit. Ask yourself, if you took a Mich -38 and UNDER 47, how would you feel rooting that home? Get me over 38, but stay under 47? That's not a spot I'd want to be, so give me other side.
THE MATH, theory justification:
Any time you make 2 plays that are 50-50 outcomes (like flipping coins), you have a 25% chance of going 0-2, 50% chance of 1-1, and 25% chance of going 2-0. If you don't know why, stop reading now! In other words, if you repeat it 4X, you should go 1-1 twice, 0-2 once, and 2-0 once. If you bet say $100 on dog and on over, that would give you and "expected" outcome of -$40 after risking $800 ($200 4 times) or an E(X) of -5% ($-40/800). As alsways, a 5% edge to the house.
I ask you, with a slim window, do you think that the Fav cover AND the total staying under can really hit 25% of the time? While each is a 50-50 play, my hypothesis is there is a built in correlation (the word Vegas hates). So what is the real outcome of the Fav and UNDER coming in? For every amount you reduce the 25% chance, you must add that to the other 2 outcomes (1-1 or 2-0). Yes, it is guess work, but it MUST add to 100% and most agree that the tiny window is NOT a 25% chance of hitting.
So let's adjust that number. If you make a SLIGHT adjustment and say that it is not 25% but rather only 20%, and conservatively add that 5% to the 1-1 outcomes (raising it to 55%) while keeping the 2-0 at 25%....the "Expected value" becomes $0! Yes, $0. Virtually no juice. For you to lose (over time) Mich/Rutgers MUST hit that small fav/under window >20% of the time. I'll take that play every time. It effectively becomes LIKELY that you either go 1-1 (-$10) or 2-0 (+$200), which is why I say even though likely to lose the juice, you are taking a shot that pays 20-1 (at least 80% of the time.) That's why I will take that play every time, no matter the teams. Believe me, going against Michigan knowing full well it would be hard for Rutgers to score was not easy to do! But I believed in the math and theory......and we all hit that "20-1" return. As soon as Rutgers got a fluke TD in first quarter, the pressure was off. It was guaranteed no worse than 1-1 at that point.
The full math at bottom, and you can see the break even point is very achievable, and some would agree this gets to a "positive outcome %" quite easily. A simple 15/60/25 gets you to a PLUS 5.5% expected outcome! I suggest there are very few realistic models that get you to a "plus" in a casino - unless you can bring Rainman with you to the Blackjack table!
Finally, while it is great when that dog needs to only score a TD or less, it can also work if you feel the big dog can SCORE even while getting waxed. Like a big 12 game with no defense :-) Say a team is laying -36 points and total is 70. 70-36=34 div by 2= 17. If I think the dog can score 17 with some certainty, its's a Rover and Over! It's nice when it gets to single digits, but the theory can also apply to bigger numbers, as long as the dog can get that number the formula generates.
Dist% E (x)
15/60/25 = +5.50%
10/65/25= + 10.70%
10/57/32 = +18.60%