Arbusers

My latest hairbrained scheme is to bet a 3 game parlay every Sunday on NFL.  All moneylines.  I take the two biggest favorites on Sunday and parlay them with the chalk on Monday's game.  Then, if the two big faves on Sunday win i can arb the parlay ticket against the dog on Monday.

For example, last week I parlayed the 2 bigest favorites (New England and Indianapolis) with the Monday favorite, Washington.  This gave me +129 odds on the parlay.  New England and Indianapolis both won, so now I essentially had Washington at +129.  Philly (Washington's opponent) was going off at +165, so I arbed it for something like 23%.

I figure as long as I the 2 big faves win 75% of the time, I am grinding out a profit for the season.  Thoughts?

If I understood you right, you place three-fold parlay, two heavy favorites and then an underdog? How long do matches in NFL usually last?
In (real) football, it is 1 hour and 45 minutes ( excluding extra time and possible small delay at start of game or 2nd half ). so when I place parlay bets, I take matches with two hour difference at least. Though better is more, as odds go can drift a lot (or steam) right before the start of the game.
If you are not covering the favorites, but only the underdog IF the favorites win, you are basically gambling and you need to calculate your things really careful. Pull some numbers out and do the math, will you really pocket some money in the long run? Favorites can lose too.
Last night for example, I had a really nice parlay arb but at the shop, I had to include three matches for the ticket to go through. So I take Netherlands to win against Andorra and it was being played same time as my other match. I didn't cover Netherlands as I said "Hey, its Andorra, they will smash them in the first half". First half ends 0-0 and I panic. If I cover Netherlands now, I would have had a 30% loss of my stake as odds drifted in-play.
Luckily they won 0-2 but point is, even heavy favorites can lose. I don't think I am doing it again.

I hope I understood you well from the start though 

I parlay three favorites.  If the first 2 win then I complete the arb by placing a straight bet on the underdog in the third game of the parlay.

I ran the numbers.  It's a slim ROI (about 4-5%) as long as the two biggest faves win 75% of the time.  I'm betting very small amounts this season to test the theory.

NFL games usually go 3.5 to 4 hours.

What were the odds on New England and Indianapolis in your example?

-525 and -425

Bullajami wrote: -525 and -425

So if you make a double-bet made of -525 and -425, you win 47% of your original stake. If you would bet 100 EUR, the profit would be 47 EUR. If you choose a tripple and make an arb on monday as in your example, with 100 EUR on the odd +129 and a counterbet on +165 then what would be the profit? Wouldn't it be like 42,5 EUR? Is there a point of making that arb? It seems like you would earn more if you would make a double-bet just on New England and Indianapolis on one coupon? Or rather you would loose less since, like Buddha mentioned, it is straight gambling.

Yikes, you are right.  Man, I am out of practice.  Thanks for the help figuring this out. 

Glad i was helpful