The additional benefit to using adjusted net yards per pass rather than passer rating is the inclusion of sacks and yards lost to sacks. Jason Lisk did a study on the Pro-Football Reference blog that found sack percentage was one of the most persistent performance stats for a quarterback changing teams, followed by completion percentage and yards per attempt. And since backup quarterbacks tend to bounce around from team to team, adjusted net yards per pass gives a better picture of a passer’s overall talent level.
The three-year league average is 6.2 adjusted net yards per pass. The average backup, meanwhile, completes 59 percent of his passes with a below-average 5.1 adjusted net yards per pass.
And since any one of the NFL’s backup passers could be thrust into a starting role at any time due to injuries, they, too, are an important piece of the puzzle — the better the backup, the better the chance of a team not missing a beat with a quarterback switch. (And ask the 2011 Colts what can happen when you don’t have a suitable understudy.)
Here’s a ranking of the league’s backups from best to worst, based on their chances of producing an above-average level of adjusted net yards per pass in a game if called into service during the 2017 season. Rookies were given an average adjusted net yards per pass figure based on historical averages of first-year NFL passers, modified for expected playing time and opportunity.
1. Matt Moore, Miami Dolphins, 54 percent chance at being better than an average starter
2. Jimmy Garoppolo, New England Patriots, 51 percent
Let’s get something out of the way early: One of the top backup options for the NFL currently lacks a team. Colin Kaepernick’s career adjusted net yards per pass (6.1) is higher than any of the backups signed to a contract this offseason and his Total Quarterback Rating (Total QBR) from 2016 (55.2) would be an upgrade over at least half of the backups in the league today, not including rookies. He’d have a 50/50 chance of providing an above-average level of adjusted net yards per pass in a given game in addition to his ability to create yardage from busted plays. That would make him the NFL’s third-best backup, if he found a team.
Among those who do have jobs, Moore got to start three games for Miami last season and completed 63.2 percent of his passes with an 8-to-3 touchdown to interception ratio. His 8.5 adjusted net yards per pass was also well-above league average (6.2).
Garoppolo performed admirably in 2016 while the Patriots waited for Tom Brady to return from his four-game suspension: 496 yards, four touchdowns and no interceptions during the first two games of the season, earning an overall grade from Pro Football Reference that was 15th in the league for the first two weeks. Injury would cause Garoppolo to miss the next two games, but his place among the league’s backups is firmly entrenched, with some teams interested in him being their starter.
3. Nick Foles, Philadelphia Eagles, 46 percent
4. Colt McCoy, Washington Redskins, 44 percent
5. Brandon Weeden, Houston Texans, 43 percent
6. Kellen Clemens, San Diego Chargers, 43 percent
7. Chase Daniel, New Orleans Saints, 43 percent
8. A.J. McCarron, Cincinnati Bengals, 42 percent
9. Chad Henne, Jacksonville Jaguars, 42 percent
10. Kellen Moore, Dallas Cowboys, 42 percent
This group is littered with former starters, backups with potential and young quarterbacks who have shown promise but could use a little more seasoning.
This list also contains backups who have a good chance of stepping into a starting role. Weeden, for example, is second on the depth chart in Houston to Tom Savage, who has two starts in two seasons in the NFL, producing a below-average passer rating (74.9) and adjusted net yards per pass (5.1). (Although that could change depending on how the just-drafted Deshaun Watson performs in training camp.)
It’s also not inconceivable to see young stars like Philadelphia’s Carson Wentz and Dallas’ Dak Prescott take a step back in their second seasons, prompting a short-term switch under center to help keep the teams’ playoff hopes on track.
Not-ready-for prime-time players
11. Trevone Boykin, Seattle Seahawks, 42 percent
12. Matt Schaub, Atlanta Falcons, 42 percent
13. Derek Anderson, Carolina Panthers, 42 percent
14. Connor Cook, Oakland Raiders, 41 percent
15. Cardale Jones, Buffalo Bills, 41 percent
16. Geno Smith, New York Giants, 41 percent
17. Landry Jones, Pittsburgh Steelers, 41 percent
18. Mitch Trubisky, Chicago Bears, 41 percent
19. Patrick Mahomes II, Kansas City Chiefs, 39 percent
The two players to keep an eye on in this group are rookies Mitchell Trubisky and Patrick Mahomes II.
Both are expected to defer to the more seasoned veterans on the squad during the regular season but it wouldn’t be a surprise if one or both got some starting reps due to poor play by the projected starters.
Trubisky has Mike Glennon in front of him in Chicago, but Glennon’s resume is far from flawless. Glennon has produced below-average adjusted net yards per pass in his three-year career (5.3) before getting passed over for Jameis Winston in Tampa.
Mahomes has a tougher path with Alex Smith to the top of the Chiefs’ depth chart after Smith posted a career-high QBR (66.1, 11th best in the NFL) last season.
But don’t be surprised if neither one of these rookies pans out. Football Outsiders’ Quarterback-Adjusted-Stats-and-Experience (QBASE) projection system gave Trubisky a 49 percent chance of being a bust in the NFL. Mahomes had a 45.7 chance.
20. Sean Mannion, Los Angeles Rams, 39 percent
21. Ryan Mallett, Baltimore Ravens, 39 percent
22. Brett Hundley, Green Bay Packers, 38 percent
23. Paxton Lynch, Denver Broncos, 38 percent
24. Scott Tolzien, Indianapolis Colts, 37 percent
25. Kevin Hogan, Cleveland Browns, 36 percent
26. Matt Cassel, Tennessee Titans, 35 percent
These guys are a heartbeat away from the starting job, and necessity is the only reason they should see the field. As a group, they have combined for 3.99 adjusted net yards per pass over the past three seasons, with none distinguishing themselves as bona fide NFL quarterbacks of the future.
Lynch, a 2016 draftee, has the best chance of breaking through to a full-time role. The quarterback in front of him in Denver is Trevor Siemian, who ranked 21 out of 30 qualified passers in QBR last season.
27. Matt Barkley, San Francisco 49ers, 31 percent
28. Drew Stanton, Arizona Cardinals, 30 percent
29. Ryan Fitzpatrick, Tampa Bay Buccaneers, 30 percent
30. Jake Rudock, Detroit Lions, 29 percent
31. Case Keenum, Minnesota Vikings, 27 percent
32. Bryce Petty, New York Jets, 27 percent
We could have just as easily called this the NSFW section.
Case Keenum ranked last in QBR in 2016 (43.4) with Ryan Fitzpatrick not too much better (45.4).
The best of the group, Matt Barkley, completed 129 of his 216 passes (59.7 percent) for 1,611 yards with eight touchdowns and 14 interceptions. The last time a quarterback threw at least that many interceptions on 216 or fewer passes was Health Schuler in 1997. Before that it was David Woodley and Todd Blackledge in 1985. In other words, Barkley’s historically inaccurate campaign of 2016 is among the best this group has to offer.