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Back to the Bench: Week 8 CPM and the Success of Spot Starters

Week 8 CPM

After potentially the most unpredictable week of the NFL season so far, watching Mike White and Justin Fields have the best games of their young careers while Geno Smith and Trevor Siemian put in productive performances as spot starters, the question arises: how frequently do we see these spot starters succeed initially?

Using our Comprehensive Passing Metric, explained here, we can go back through the past 15 years and look at some of these passers who have excelled as a secondary option.

Skipping past some QBs like late-season 2010 Nick Foles and 2014 Ryan Fitzpatrick, who were the most successful after formally winning the job, we arrive at a surprising top spot: Brock Osweiler. In a 2017 relief appearance with Denver in Week 15, Osweiler replaced an injured Trevor Siemian (who was himself starting after Paxton Lynch was injured) and posted an outstanding 8.00 CPM in a 12-point win over the Colts. 

Entering the game at the beginning of the second quarter, Osweiler posed enough threat to open run lanes for C.J. Anderson, putting up 11.4 yards per attempt while adding three total TDs along with no turnovers or sacks. Not known as a rusher, Osweiler was facing a 3rd-and-9 with a 10-point deficit near the end of the first half and ran all of 18 yards (the third-longest rush of his career) to score and jumpstart the comeback. 

With a subsequent lengthy drop until we reach our next-highest passer, it becomes apparent just how rare it is for passers to be successful in a short-term relief stint.

The vast majority of teams never have to rely on an option other than the established starter or the up-and-comer. However, we do eventually arrive at the 2018 edition of Matt Barkley, recording a 7.02 CPM in his only action (and start) of the season. With rookie Josh Allen injured and backup Nathan Peterman unimpressive the week prior, Barkley led the Bills to a rout of the rival Jets with a clean, efficient performance of 2 TDs and 1 sack.

While building a 28-point halftime lead, Barkley eschewed the expected “dumpoffs and screens” strategy and instead took his shots downfield with a 14.6 average depth of target while gaining over 71% of his yards through the air. He has not started since, but is currently on the Titans' practice squad.

Carson Palmer opened the 2014 season as the starter for the Arizona Cardinals, but a Week 1 shoulder injury forced Drew Stanton into the starting role for the next three weeks (and later a five-game stretch after Palmer was injured again). Stanton was a 2008 second-round pick of Detroit but had started only four games for the team and hadn’t played a snap from 2011-2013. After a game to shake off the rust, Stanton’s Week 3 win over the 49ers was impressive considering his best rusher (Andre Ellington) averaged only 3.4 yards per carry and WR Larry Fitzgerald lost a rare fumble (just his second in the prior 107 games). Regardless, Stanton’s 7.01 CPM was a product of an explosive passing attack that picked up five passes of 20+ yards and managed 74% of his yards through the air. He has never been quite as successful since, but the team will certainly be thankful for this unexpected win after sneaking into the playoffs as a wildcard. 

Week 8 CPM

Although the talk this week is all about the upheaval of the expected quarterback spectrum, it was overall a poor week for quarterbacks in general.

No QB bettered Drew Stanton’s week listed above, and Jimmy Garoppolo came closest with a 6.83 CPM. Geno Smith surprisingly finished second at 6.68, while Matthew Stafford and Josh Allen continued their excellent seasons with 6.57 and 6.05 scores, respectively. At fifth, we finally arrive at Mike White and his 5.63 CPM. White benefitted from his strong 8.48 completion percentage over expected, but was knocked for his 2 INTs, 2 sacks, and very low 2.98 completed air yards per attempt. 

The next five are the only QBs to pass a 5.0 this week: Justin Fields (5.51), Jalen Hurts (5.41), Joe Burrow (5.35), Teddy Bridgewater (5.21), and Sam Darnold (5.09).

The spot starters were fairly decent, with Trevor Siemian finishing 13th with a 4.79 and Cooper Rush securing 19th with his 4.36, but the bottom ten is a grab-bag of disappointing performances from MVP hopefuls including Patrick Mahomes (4.05), Kyler Murray (3.92), and Justin Herbert (3.39). 

Who are the top QBs so far this season?

Week 8 CPM Rankings for 2021

Excluding the single qualifying games of Tyrod Taylor and Case Keenum, these are the top QBs of the first eight weeks of the season by median game CPM.

Stafford has been top by median for several weeks, but actually only just took the top by mean (read: average) this week from Josh Allen. What else can we see from this graph? Wider colored bars show QBs who are less consistent, so we can appreciate the consistency of Josh Allen, Dak Prescott, Joe Burrow, and Russell Wilson — Mike White has two qualified games, so it necessarily is a thinner colored bar.

On the other hand, the extending black lines show the floor and ceiling of passers so far, with outliers excluded (but shown in the light grey dots).

Patrick Mahomes, Josh Allen, and Tom Brady have hit heights this year that no other passer has matched. Stafford having the fourth-highest peak is simply outstanding given how short his bar is, meaning he hits that level much more frequently.

Finally, several passers have had relatively low floors: Matt Ryan, Ryan Tannehill, Derek Carr, Patrick Mahomes, and Justin Herbert. This is a surprising grab-bag of QBs, but a real Super Bowl run will require better play.