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NFL Win Probabilities and Chances of Going Over/Under Win Totals

Updated August 16th, 2021
Published July 28, 2020

Each spring, sportsbooks give bettors a gift when they release the opening lines for every week of the upcoming NFL season. The gift is not the ability to place a bet on a Week 13 game you think presents value, but rather the pieces of a (complex) puzzle that when put together properly, give you a detailed picture of what sportsbooks are expecting from each team this season.

Using these opening NFL lines, I’ve already put together SBD’s NFL Power Rankings, which is based on an ATS +/- for all teams from Weeks 1-16. I’ve gone one step – or maybe 87 steps – further with these opening spreads, though.

We’re going to Tarantino this one. Let me give you the end result quickly, and then we’ll take our time in walking back through how we got here.

Best Over/Under Bets on 2021 NFL Win Totals

Teams to Bet OVER on Win Total Win Total Over Probability Teams to Bet UNDER on Win Total Win Total Under Probability
Buffalo Bills 10.5 67.5% Washington Football Team 8.5 73.3%
Las Vegas Raiders 6.5 62.5% New England Patriots 9.5 70%
Baltimore Ravens 10.5 61.4% Miami Dolphins 9.5 67.5%
San Francisco 49ers 10.5 60.4% Tennessee Titans 9.5 67.4%
Tampa Bay Buccaneers 11.5 58% Los Angeles Chargers 9.5 66.6%

>> Use a Risk-Free Bet Up to $1,000 at FanDuel on the Washington Under <<

After winning 13 games in 2020, the Buffalo Bills’ win total for 2021 is set at 10.5. My formula says the Bills have a 67.5% chance of going over that total, the best over bet in the league.

On the other hand, the Washington Football Team won the NFC East last year with a 7-9 record. Their win total for 2021 is listed at 8.5, and my calculation gives them a 73.3% chance of going under.

It’s no coincidence that the 49ers are one of the best over bets this season, as they have the easiest schedule in the NFL based on our proper NFL SOS model.

These are not the only win totals bets showing an edge, however. There are a total of 12 with an over/under probability greater than 60%. You can see the rest below.

But now that you know our best bets, let me tell you how I ended up here. I’m calling this SBD’s Win Prob calculation.

What Is SBD’s Win Probability Calculation?

As I said earlier, I started with the opening lines for every game of the 2020 NFL season. These are the truest odds you can get your hands on. Money has not influenced them yet and it’s the closest thing you’ll find to the sportsbooks’ true perception of each team – they are still considering the public perception of each team, but they don’t have as good of a read on the public before money comes in.

And while there will be teams who surprise us every season, sportsbooks have a track record of being pretty accurate in how they view teams.

I knew my ATS +/- (or SBD NFL Power Ranking) would help with Super Bowl and playoff futures. But I wasn’t able to find a ton of great win total trends or correlations from that calculation. So I started thinking about what I could do with these spreads to help with win totals.

And then it hit me! I realized I could use these opening lines to poke holes in the 2021 NFL win totals that have been influenced by money and public perception.

Here was my thought process:

  1. Convert the spreads to implied probabilities to simply win the game;
  2. Calculate every win-loss combination for a 16 17-game season – did you know there are 65,536 131,072? There may only be one way to win 17 games, and 17 different ways to go 15-1 (depending which game you lose), but there are 24,310 different ways to go 8-9;
  3. Going one team at a time, input their probabilities to win or lose each game of the season;
  4. Add together all win-loss combinations that result in the same number of wins.

After doing that work, I now had the probability for each team to win zero through 17 games this season.

Full disclosure, I see two very minor flaws with this: (a) I did not factor in the probability of a game ending in a tie; and (b) while many of these spreads will be different from what we see at their more traditional opening (a week prior to the game), Week 18’s spreads will likely be much different than what we have now.

But I don’t see either of these having much of an effect on the teams whose SBD Win Prob is way out of line with their win total at sportsbooks – we’ve seen nine ties in the NFL since 2012, which comes out to one per season, and if any of your over/under bets don’t have anything to play for in Week 17, it probably means your bet has already been graded.

SBD’s Win Probability Data

The image above shows the possible records in a 17-game season across the top, from 0-17 all the way to 17-0. Each cell indicates the probability of that team winning that number of games.

Below is the data in a more focused view, rounded to the nearest tenth and excluding the probabilities for zero to three and 14 to 17 wins, since no team is favored to win that few/many.

Simplified View of SBD’s Win Prob Data

Team 4-13 5-12 6-11 7-10 8-9 9-8 10-7 11-6 12-5 13-4
Arizona Cardinals 1.2% 3.5% 8% 13.8% 18.7% 19.7% 16.3% 10.6% 5.3% 2%
Atlanta Falcons 3.4% 8.1% 14.3% 19.2% 20% 16.2% 10.2% 4.9% 1.8% 0.5%
Baltimore Ravens 0% 0.2% 0.9% 2.6% 2.6% 11.6% 17.3% 20.3% 18.6% 12.9%
Buffalo Bills 0% 0.1% 0.5% 1.6% 1.6% 9.7% 16.1% 20.8% 20.5% 15%
Carolina Panthers 5.8% 11.6% 17.4% 20.1% 18.1% 12.8% 7.1% 3% 1% 0.3%
Chicago Bears 2.5% 12.8% 18.3% 20.3% 17.4% 11.7% 6.1% 2.5% 0.8% 0.2%
Cincinnati Bengals 11.9% 17.8% 20.3% 17.9% 12.5% 6.9% 3% 1% 0.3% 0.1%
Cleveland Browns 0.4% 0.4% 1.6% 4.4% 9.3% 15.5% 20% 19.9% 15.2% 8.7%
Dallas Cowboys 0.7% 2.2% 5.7% 11% 16.8% 19.9% 18.5% 13.4% 7.4% 3.1%
Denver Broncos 1.6% 4.6% 9.7% 15.8% 19.8% 19.3% 14.7% 8.6% 3.9% 1.3%
Detroit Lions 20.4% 21.4% 17% 10.4% 5% 1.9% 0.6% 0.1% 0% 0%
Green Bay Packers 1.1% 3.3% 7.5% 13.2% 18.2% 19.8% 16.8% 11.2% 5.7% 2.2%
Houston Texans 22.5% 20.5% 14% 7.4% 3% 1% 0.2% 0.1% 0% 0%
Indianapolis Colts 0.2% 1% 3% 7.1% 13% 18.5% 20.4% 17.5% 5.7% 5.6%
Jacksonville Jaguars 7.6% 13.7% 18.8% 19.9% 16.5% 10.8% 5.5% 2.2% 0.7% 0.2%
Kansas City Chiefs 0% 0% 0.1% 0.4% 1.4% 4% 8.8% 15.4% 20.8% 21.4%
Las Vegas Raiders 5.7% 11.6% 17.6% 20.3% 18.3% 12.8% 7% 2.9% 1% 0.2%
Los Angeles Chargers 1.4% 3.9% 8.5% 14.2% 18.8% 19.5% 15.9% 10.1% 5% 1.8%
Los Angeles Rams 0.1% 0.5% 1.8% 4.8% 9.8% 15.8% 19.9% 19.5% 14.7% 8.4%
Miami Dolphins 1.3% 3.9% 8.6% 14.5% 19.1% 19.6% 15.8% 9.8% 4.7% 1.7%
Minnesota Vikings 1.3% 3.7% 8.3% 14.1% 18.7% 19.6% 16.1% 10.3% 5.1% 1.9%
New England Patriots 1.7% 4.6% 9.6% 15.4% 19.3% 19% 14.8% 9% 4.2% 1.5%
New Orleans Saints 0.7% 2.2% 5.5% 10.7% 16.3% 19.6% 18.5% 13.7% 7.9% 3.4%
New York Giants 6% 11.8% 17.5% 20% 17.9% 12.6% 6.9% 3% 1% 0.3%
New York Jets 10.7% 16.8% 20.2% 18.8% 13.7% 7.9% 3.6% 1.3% 0.4% 0.1%
Philadelphia Eagles 8.6% 14.7% 19.2% 19.5% 15.6% 9.9% 4.9% 2% 0.6% 0.1%
Pittsburgh Steelers 1.1% 3.5% 7.9% 13.9% 18.9% 20% 16.5% 10.5% 5.1% 1.9%
San Francisco 49ers 0% 0.2% 0.9% 2.6% 6.3% 11.9% 17.7% 20.5% 18.5% 12.5%
Seattle Seahawks 0.5% 1.8% 4.7% 9.7% 15.5% 19.5% 19.2% 14.8% 8.8% 3.9%
Tampa Bay Buccaneers 0% 0.1% 0.2% 0.9% 2.8% 6.7% 12.6% 18.6% 21.3% 18.4%
Tennessee Titans 1.4% 4% 8.7% 14.5% 19% 19.4% 15.7% 9.9% 4.8% 1.8%
Washington 5.4% 10.8% 16.5% 19.6% 18.3% 13.5% 7.9% 3.6% 1.3% 0.4%

If you shop your sportsbooks properly, you will find every single team’s win total offered with a hook, so there is no possibility of a tie.

Based on the SBD Win Prob calculation, here’s each team’s probability to go over/under their respective win total this season.

Over/Under Probabilities Based on SBD Win Prob

Team Win Total Over Probability Under Probability
Arizona Cardinals 8.5 54.5% 45.5%
Atlanta Falcons 7.5 53.7% 46.3%
Baltimore Ravens 10.5 61.4% 38.6%
Buffalo Bills 10.5 67.5% 32.5%
Carolina Panthers 7.5 42.3% 57.7%
Chicago Bears 7.5 38.7% 61.3%
Cincinnati Bengals 6.5 41.7% 58.3%
Cleveland Browns 10.5 48.7% 51.3%
Dallas Cowboys 9.5 43.5% 56.5%
Denver Broncos 8.5 48.1% 51.9%
Detroit Lions 5.5 35.1% 64.9%
Green Bay Packers 9.5 36.8% 63.2%
Houston Texans 4.5 46.2% 53.8%
Indianapolis Colts 9.5 57.3% 42.7%
Jacksonville Jaguars 4.5 55.8% 44.2%
Kansas City Chiefs 12.5 49.1% 50.9%
Las Vegas Raiders 6.5 62.5% 37.5%
Los Angeles Chargers 9.5 33.4% 66.6%
Los Angeles Rams 10.5 47.2% 52.8%
Miami Dolphins 9.5 32.5% 67.5%
Minnesota Vikings 8.5 53.6% 46.4%
New England Patriots 9.5 29.9% 70.1%
New Orleans Saints 9.5 44.8% 55.2%
New York Giants 7.5 41.7% 58.3%
New York Jets 6.5 45.7% 54.3%
Philadelphia Eagles 6.5 52.5% 47.5%
Pittsburgh Steelers 8.5 54.4% 45.6%
San Francisco 49ers 10.5 60.4% 39.6%
Seattle Seahawks 9.5 48.3% 51.7%
Tampa Bay Buccaneers 11.5 57.9% 42.1%
Tennessee Titans 9.5 32.6% 67.4%
Washington Football Team 8.5 26.8% 73.2%

In the table above, I’ve put any probability above 57% in bold font. We already highlighted our top ten bets at the beginning of this, but there are many more that present an edge for the bettor.

When you factor in the odds you’re getting on the over/unders above, here are the bets with the biggest edge for the bettor based off the SBD Win Probability:

  1. Washington Football Team Under 8.5 (22% edge for bettor – under odds are -105, which is an implied probability of 51.2% vs the SBD Win Prob of 73.2%)
  2. New England Patriots Under 9.5 (13.6% edge for bettor – under odds are -130, which is an implied probability of 56.5% vs the SBD Win Prob of 70.1%)
  3. Miami Dolphins Under 9.5 (11.9% edge for bettor – under odds are -125, which is an implied probability of 55.6% vs the SBD Win Prob of 67.5%)
  4. Tennessee Titans Under 9.5 (11.8% edge for bettor – under odds are -125, which is an implied probability of 55.6% vs the SBD Win Prob of 67.4%)
  5. San Francisco 49ers Over 10.5 (11.6% edge for bettor – over odds are +105, which is an implied probability of 48.8% vs the SBD Win Prob of 60.4%)

Some other teams who are showing a significant edge vs the odds, but whose over/under probabilities are not greater than 57% include: (1) Arizona Cardinals over 8.5 – 6.9% edge vs +110 odds; (2) Denver Broncos under 8.5 – 5.4% edge vs +115 odds; (3) Jacksonville Jaguars over 6.5 – 7% edge vs +105 odds; (4) Los Angeles Rams over 10.5 – 5.6% edge vs +140 odds; (5) Minnesota Vikings under 8.5 – 5.6% edge vs +145 odds; and (6) Pittsburgh Steelers over 8.5 – 7.9% edge vs +115 odds.

Results from Last Year

Record Profit
8-5 +1.34 units

In 2020, the first year I did this calculation, we spit out 13 win total bets that had a probability greater than 57%. Six of them were over bets and seven were unders. If you risked one unit on each of them, you would have made 1.34 units last year.

It’s not a big return, but it is still a return.

We hit on the following bets: (1) Bears over 7.5, (2) Packers over 8.5, (3) Colts over 8.5, (4) Chiefs over 11.5, (5) Falcons under 7.5, (6) Broncos under 7.5, (7) Jets under 6.5, and (8) Eagles under 9.5.

We missed on the following: (1) Vikings over 8.5, (2) 49ers over 10.5, (3) Browns under 8.5, (4) Raiders under 7.5, and (5) Dolphins under 6.5. The San Francisco bet got chewed up early as the injury bug bit the reigning NFC Champions hard in the first few weeks. Fortunately, we did head into the final week of the season with an opportunity to hedge the Las Vegas bet.

Here’s to a better return in 2021!

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