How Vegas oddsmakers set lines for NFL games is equal parts science and art and varies from sportsbook to sportsbook. But suffice it to say no position has a greater impact on the point spread than a team’s starting quarterback.
Thanks to the proliferation of advanced metrics across the internet, we can at least get a sense for how oddsmakers might approach assigning a value to quarterbacks.
EPA and CPOE Composite explained
Expected Points Added (EPA) is a stat that seeks to measure the value of individual plays in terms of points. This is done by calculating the Expected Points (EP) of the down, distance and field position situation at the start of a play and contrasting it with the situation at the end of the play.
A three-yard gain on first-and-10 is substantially different than a three-yard gain on third-and-two, something not usually captured in traditional statistics. The Expected Points framework helps translate raw yardage figures into actual value.
Meanwhile, Completion Percentage Over Expected (CPOE) is calculated by Next Gen Stats, utilizing proprietary tracking data to estimate the likelihood a given pass is completed at the time it is thrown, averaging all of those expected percentages, and then subtracting that from the actual completion percentage of a player for each game.
Finally, EPA + CPOE Composite is a blend of both stats and is considered to be one of the most predictive stats to evaluate QB performance from year to year.
Using quarterback EPA + CPOE Composite data available on rbsdm.com and plugging in assumptions for dropbacks per game, we can estimate every quarterback’s value to the point spread.
Since most backup QBs haven’t accrued enough snaps to form a meaningful sample size, we took a slightly different approach to valuing backups. First, we ranked each backup from best to worst — an exercise that admittedly involves some guesswork and projection in its own right — and then looked at the historical performance of backups in general to establish a range.
NFL QB point spread values
A few thoughts
Matthew Stafford
Stafford’s reputation precedes his actual production at this point. Over the last five seasons, Stafford has been worth an average of 4.1 points per game by our math, with a median of just 3.8 points.
Going back even further than that, the last time Detroit came close to winning a playoff game was after the 2014 season, when the Lions got hosed in Dallas. In that season, Detroit’s defense was No. 1 in Football Outsiders’ DVOA metric, while the Lions’ offense, with Stafford, Calvin Johnson and Golden Tate in their primes, was just 19th.
Either the Lions’ coaching staff was the most incompetent in the history of organized sports (possible) or Stafford’s just not as good as people seem to think he is. We gave Stafford a slight boost for the “McVay effect” he might get in Los Angeles, but we are lower on Stafford than the market.
Jared Goff
If you compare Goff’s last four seasons in L.A. to Stafford’s final four years in Detroit from an advanced numbers perspective, the value delivered on a per-play basis is very similar between the two.
However, if you focus exclusively on just the last two seasons, Stafford was worth about 1.5 points per game more than Goff, which is likely why the Rams viewed Stafford as a clear upgrade, even if the narrative is a bit louder than the reality.
The biggest difference between Stafford and Goff can be seen when opposing defenses bring pressure. According to Pro Football Focus, the average NFL passer rating from a clean pocket last season was 104. When opposing defenses were able to generate pressure, that average dropped to 66.
For Goff, those splits are even more staggering. Goff had a passer rating of 106 when throwing from a clean pocket, but dropped all the way to a dismal 46 when pressured. That 60-point drop in passer rating — compared to the 38-point average decline — means Goff was approximately 58% worse under pressure than the average NFL QB. (Stafford, by contrast, had a 98 passer rating with a clean pocket and dropped only to 92 under pressure.)
Of the 36 quarterbacks that appeared in at least eight games last season, the only QBs worse than Goff under pressure were the Pats’ Cam Newton, Miami’s Tua Tagovailoa, Washington’s Alex Smith, Denver’s Drew Lock and San Francisco’s Nick Mullens.
That group includes a rookie (Tua), a guy whose leg was held together with Play-Doh™ (Smith), a backup (Mullens), and two hanging-on-by-a-thread starters (Newton and Lock). In other words, not the type of company a QB wants to keep when he’s making $26 million and has a Super Bowl start on his resumé.
Aaron Rodgers
When we dove into the advanced numbers, we were surprised to see how dismal Rodgers’ three-season stretch from 2017-19 was, at least compared to the standard he set for himself.
In 2016, Rodgers turned in an MVP-caliber season in which we had him valued at about 7.1 points per game. Over the next three seasons though, Rodgers was worth just 4.1 points, which may shed some light on the Packers’ controversial decision to draft Jordan Love.
Whether it was a spark lit by the drafting of Love or perhaps a developing chemistry with coach Matt LaFleur, Rodgers absolutely erupted in 2020, when we had him estimated as being worth 7.9 points, an astronomical number.
While last year’s figure might not be sustainable, we think it’s closer to the truth than the three seasons that preceded it, which is how we landed on 6.5 points per game for Rodgers.
Andy Dalton/Justin Fields
Dalton has been worth fewer than 3 points in each of the last four seasons, looked wretched in Dallas last season, and needs to be plastered to the bench at this stage of his career.
Why wait on Justin Fields? He’s a product of the Georgia prep football machine, a former MVP of the Elite 11 quarterback competition, a five-star recruit and the No. 1 dual-threat QB in the class of 2018. He spent three seasons practicing and playing for premier college programs in Georgia and Ohio State, went 20-2 as a starter for the Buckeyes, and produced 86 passing and rushing touchdowns against just 9 interceptions.
At least with Trey Lance you can argue he was a lesser-known commodity in a weaker high school football state (Minnesota) and started for only one season at FCS North Dakota State. But that is simply not the case with Fields, who has an elite pedigree and track record of production. If Matt Nagy wants to remain even remotely employable, Fields needs to start right now.
Kyler Murray
Full transparency: We are shameless, unabashed Kyler fanboys. In 2018, Patrick Mahomes burst onto the scene in his second NFL season and won MVP. In 2019, Lamar Jackson turned the same trick, winning a sophomore year MVP. Heading into 2020, the question was whether lightning could strike a third time with Kyler Murray.
Through 11 games, Murray was in the mix, with an EPA + CPOE Composite of .150, which translates to about 6.7 points per game when factoring in Murray’s touches. In a Week 11 loss to San Francisco, Murray appeared to injure his shoulder. From Week 12 through the rest of the season he posted a meager EPA + CPOE of .056, meaning his efficiency dropped by more than 60%.
Assuming Murray is healthy, we still think he’s an MVP candidate, capable of being worth 7 points or more to the Vegas spread, and even if we had to wait until Year 3, this kid has the tools and explosiveness to make it worth the wait.
