NFL Monday Night Props - Have I Found Free Money?

Ok so I have a few books that I use in order to find the best lines, and I came across something today that made me a little excited...

Site A has a prop for Over/Under 3.5 FG in tonight's game

Under -130
Over +100

Site B has a prop for Over/Under 3.5 FG in tonight's game

Under -170
Over +145

Now if i risked $130 to win $100 on the under on Site A, and $100 to win $145 on the over on site B, I would guaruntee myself either a profit of $15 (If over hits) or break even.

Anyone ever had any similar instances they would care to share? Any other insight on my findings would be greatly appreciated as well.

I'm going to be keeping an eye out for these type of things more often now.

hi i´ve heard about that searching on the web!!and now that i know sombedody(you)found something i´m excited to!!you have to bet instead of $130 And $100,$1300 and $1000....you just found the filosofal rock!!good for you!!!and best wishes!!!

I feel touched that you used your 1st post since joining over a year ago on my topic!

Best wishes to you too!

Good job shopping around for the best value on this particular prop wager. 

A similar wager is betting a small favorite (3 points or less in football, not sure the cutoff in basketball) at -110 and then betting the moneyline on the underdog in the same game.  If the underdog wins outright your profit is the difference between the ML and your side wager.  If the favorite covers, you push.  You only get screwed on both bets if the favorite wins, but does not cover. 

Firebird

Too much risk for me in that sense.