NFL Middle Tables
NFL Scoring Margins
As mentioned in other areas on the site, the Australian betting website listed in the References section has been keeping detailed data of NFL gambling lines and score outcomes since 2006. A quick download of their excel spreadsheet gives everything needed to construct the following data tables and graphs below. These graphs and tables come in handy when assessing the value of point spread line moves and whether or not it is worth it to pursue opportunities for a middle. The tables comprise the data from the start of the 2015 season through Week 4 of the 2021 season. This represents a total of 1,668 games. The reason for the reduced data (not using 2006-2014) is due to the extra point rule change that started in 2015 which increased the length of extra point kicks. I believe this has altered the outcome percentages enough where only the data from games with this rule in place should be looked at. We still have a decent data sample size to feel comfortable enough using it at this point.
NFL Game Point Totals
A similar exercise can be performed when it comes to point totals on NFL games. Point totals can also represent a great opportunity for middles and +EV bets when looking at multiple sportsbooks. The graphs and tables below are comprised of data from 2015 to Week 4 2021 for a total of 1,669 games to include only games with the longer extra point rule in place.
An example of a recent opportunity for a +EV point total middle is demonstrated below:
Sportsbook 1: Point Total Line U51 +100 Sportsbook 2: Point Total Line O50 -110
Using the point total tables above, we can calculate whether or not this represents a +EV betting opportunity. The chances of the game ending with 50 total points is 2.63%. The chances of the game ending with 51 total points is 3.91% Subtracting the chance of the game ending with 50 or 51 points leaves a remaining 93.46% possibility of another outcome. If we assume an equal chance that the game will end with more than 51 points or less than 50 points then there is a 46.73% chance for each of those outcomes to occur. With the percentages for all of these possible outcomes estimated, we can now do a Expected Value (EV) calculation.
Bet $100 on the U51 +100 line Bet $100 on the O50 -110 line
Game Outcome Scenarios Point Total < 50: Win $100 on U51 bet and lose $100 on O50 bet for $0 profit. % Chance of Outcome = 46.73% Expected Value = 0.4673 x $0 = $0
Point Total = 50: Win $100 on U51 bet and push on O50 bet for $100 profit. % Chance of Outcome = 2.63% Expected Value = 0.0263 x $100 = $2.63
Point Total = 51: Win $90.91 on O50 bet and push on U51 bet for $90.91 profit. % Chance of Outcome = 3.91% Expected Value = 0.0391 x $90.91 = $3.55
Point Total > 51: Win $90.91 on O50 bet and lose $100 on U51 bet for a $9.09 loss. % Chance of Outcome = 46.73% Expected Value = 0.4673 x ($9.09) = ($4.25)
Total Expected Value (EV) = $0 + $2.63 + $3.55 + ($4.25) = $1.93
The above calculation shows that we should expect to make $1.93 per $100 bet one each side of this middle scenario in the long run of making a bet like this. This is a great example to show how quickly the margin can switch from book advantage to the player when books aren’t aligned with their point total lines. While $1.93 doesn’t seem like much, I like to think of it as free money on the ground whenever we are given the opportunity for +EV bets. You have to trust the numbers and pick that money up whenever possible. It’s a fun way to take very little risk and have the chance for a nice payout if one of your middle numbers hit (50 or 51 in this case).