How Vegas Spreads Affect Fantasy Football Quarterback Performance

The unpredictability of sports is what makes them endlessly entertaining. Generic phrases like "any given Sunday" remind us that any team can win, regardless of the odds.

Improbable moments like Kevin Kolb leading the Cardinals to a win in New England versus the Patriots in 2012 keep us guessing.

Michigan State lost to the Middle Tennessee State Blue Raiders in one of the biggest upsets in March Madness history last month.

The Undertaker lost to Brock Lesnar at Wrestlemania and stunned millions of fans.

Upsets in sports are as inevitable as Mike Holmgren publicly expressing interest in a head coaching job that he wasn't even offered. 

These three upset examples are outliers. The truth is, the team that's favored is going to win the game outright more times than not. And we can use this information to our advantage when forecasting  defensive performance as well as other positions.

Today, though, we're going to look at which quarterbacks have excelled as favorites.

Playing Favorites

In order to conduct this study, I used the Rotoviz Game Splits App, which allows you to break down how a player has performed in specific situations. I ran a test on every quarterback who attempted a minimum of 100 passes in 2015. 

Next, I split up the results by how they performed when they were favorites and then did the same for underdogs. Not just for 2015 -- over their entire career. I also weeded out the quarterbacks who aren't starters, or only started a handful of career games. I also removed Peyton Manning and Matt Hasselbeck since they've retired and no one needs their numbers anymore.

It should also be noted that Marcus Mariota actually had the best home/road splits, but he has played only three games as a favorite. That's probably too small of a sample size.

In this new pool of 34 quarterbacks, the favored quarterback scored an average of 19.19 standard fantasy points, while underdogs scored an average of 17.90, a difference of about 1.29 points.

For reference, Tom Brady has averaged 3.02 more points per game as a favorite than he has as an underdog. Drew Brees has averaged 5.65 more points per game as favorite than he has as an underdog. 

The entire list of quarterbacks, though, is listed below, sorted by the largest discrepancy between home and road success.

Tyrod Taylor finished at the bottom of the list with a reverse home-road split. His sample size is small, but worth noting. Brian Hoyer and Jameis Winston also finished with wonky home/road splits. These three quarterbacks all have smaller sample sizes, though, so I wouldn't automatically fade them as favorites.

Veteran quarterbacks like Eli Manning and Philip Rivers have scored slightly worse as favorites throughout their career. They have large sample sizes of over 150 games each, but this difference isn't actionable.

Cam Newton has been a fantasy football monster since Day 1 in the NFL. His scoring as a favorite and as an underdog are very similar -- and are also really high -- and he averages the highest scoring per game as an underdog among all active quarterbacks. Cam is mostly matchup-proof, minus Von Miller.

Ben Roethlisberger appears in the middle of the list for his career. However, with his high-powered offense in 2015, he averaged 7.5 more points per game as a favorite.

Actionable Advice

Looking at this list and the stats can possibly help us predict success, but most results won't help you when picking your quarterback on Sundays. However, the top three on our list may also be the most actionable when it comes to picking your guy.

Matthew Stafford, Blake Bortles, and Aaron Rodgers round out our top three.

Rodgers is a fantasy football god. But even with Rodgers, you're better off starting him as the favorite.

In 100 career games as a favorite, he's averaged a smoldering 25.96 fantasy points per game, the highest average of any active quarterback. Scoring 19.86 points as a dog is still rather impressive, but it shows us that he is more likely to succeed as a favorite.

When Rodgers has faced a passing defense ranked in the top half of the league, he's scored an average of 22.4 points per game. In games against bottom-half pass defenses, he's scored an earth-scorching 27.07 points per game. If you're going to pay top dollar for Rodgers in daily fantasy, make sure he is favored against a poor passing defense.

Bortles has only played six career games as a favorite, so this is a bit of a small sample. In these six games, though, he's scored an average of 6.28 fantasy points more as a favorite.

The average of 25.37 fantasy points per game as a favorite is higher than Drew Brees' career average of 24.77. Again, this is a small sample size.

The Jaguars have rarely been favorites in their games, but Bortles has flourished in those matchups. I dug a bit further to see how Bortles did against skilled passing defenses, and in games against an above-average pass defense ranked in the top 16, Bortles scored an average of 17.41 fantasy points. But in games versus a bottom-half pass defense, he scored 24.75 fantasy points on average.

In other words, in his first two seasons, he has thrived against lesser teams.

Stafford's scoring as a favorite surprised me the most. I'm not as surprised as the WWE fans when the Undertaker lost at Wrestlemania, but I'm pretty damn surprised -- he's averaged 25.43 fantasy points in standard scoring when he was the favorite. 

This will really put things into perspective:

Only Newton and Rodgers have averaged more points per game as favorites than Stafford.

In 2015, Stafford was the favorite in five games. In those five, he went bananas to the tune of 31.04 points per game. As an underdog, he averaged 19.44.

Stafford lost Calvin Johnson to retirement, but his loss should be our gain, as this should make Stafford even cheaper on daily fantasy sports sites. The moment I see him listed as a favorite at a reasonable price on FanDuel, I'm firing him up.