The Stats Say Washington Should Have Signed Colin Kaepernick (And It’s Still Not Too Late!)

After starting quarterback Alex Smith broke his leg in Week 11, the Washington Redskins rode their journeyman backup, Colt McCoy, to two losses and a 7-3 deficit against the Philadelphia Eagles in Week 13 before he also broke his leg. Struck with misfortune at the most important position in professional sports, Washington trotted out Mark Sanchez, a player signed off the street to back up McCoy.

This obviously didn’t work out well. Sanchez had not played an NFL game since 2015, and he went on to record the worst expected points added (EPA) per play (-0.627) of any NFL QB in 2018 with at least 20 pass attempts. This includes Nathan Peterman. Sanchez was promptly benched in a blowout 40-16 loss to the Giants in Week 14. His replacement: Josh Johnson, a 32-year-old journeyman who has played for 12 different NFL teams and who reportedly had to play Madden to learn the names of his new teammates.

Hindsight is 20-20, but it’s worth asking if this skid could have been avoided — or at least somewhat mitigated — had Washington signed free agent Colin Kaepernick instead of Sanchez. It’s even worth wondering if they still should sign him. A playoff berth for the Redskins is highly unlikely, but they are still not mathematically eliminated. Could signing Kaepernick help the team win out, finish 9-7, and give them a shot at the postseason?

Let’s look at this as a purely football decision and put aside any public relations baggage that would come with signing Kaepernick. Let’s also assume that Kaepernick is in decent enough shape to put on a jersey right now and play at the levels we have seen from him in the past. (For what it’s worth, he has said that he’s remained in game shape.)

I looked at standard measures of quarterback performance like yards per attempt along with more advanced stats like EPA per play and success rate, which measures how often a player keeps his team “on schedule” or on track for a first down. The first question — “Should Washington have signed Sanchez or Kaepernick?” — is straightforward to answer.

Using data from Ron Yurko’s EPA model, I analyzed both of the QBs over their careers to see which one has been better at creating expected value per pass. I also broke out the contribution of yards after the catch to help with the comparison. Yards after catch is probably best thought of as the product of scheme and wide receiver skill, but passes that are on time and on target from a QB surely help as well.

The contest wasn’t a contest at all. Kaepernick is superior to Sanchez over his career by a large margin and across a wide spectrum of metrics. Kaepernick’s career yards per pass attempt is higher than Sanchez’s by more than half a yard. His career EPA per play is on the order of 40 times better than Sanchez, despite their yards after catch EPA per play being relatively close.

Kaepernick has been far from perfect. His career yards per attempt is no better than league average, and his career completion percentage is low at 59.8 percent. His greatest flaws as a passer show themselves at the intermediate depths, where his completion percentage is well below average. Whether this is because he struggles to make reads or because his decision making on slower developing routes is poor is an open question. What is clear is that neither Kaepernick nor Sanchez is particularly accurate across most depths of target.

Kaepernick, however, has also affected game outcomes with his legs. He is not exactly young anymore, though, at 31 years old; we might expect a decline in rushing effectiveness that typically accompanies NFL QBs as they age. Still, Kaepernick’s legs are fresh, and Sanchez has never shown the ability to add value on the ground.

Meanwhile, Kaepernick adds roughly equal value to his team whether he runs or passes the football, making him a legitimate dual threat. It was this ability that took the San Francisco 49ers within 5 yards of winning the 2012-13 Super Bowl. What’s more, the league has become more open to the air raid concepts Kaepernick ran at the University of Nevada, as evidenced by the ascendancy of Kansas City’s Patrick Mahomes, who played in an air raid system at Texas Tech. There are legitimate reasons to believe that Kaepernick could still fit in the league.

Kaepernick’s path to snaps in Washington is blocked by current quarterback Johnson, who has just 193 total career pass attempts to his name and, like Sanchez, is a year older than Kaepernick. When we look at his career efficiency numbers compared with Kaepernick’s, we can see why Johnson hasn’t been allowed much opportunity to throw. Plays with Johnson under center have resulted in negative value for his teams.

So what about moving forward? Could Kaepernick help Washington win? Our best predictors of future performance at the QB position are career efficiency measures like yards per attempt and EPA per play — far more useful than looking only at Kaepernick’s most recent season.

The table below shows every player who has attempted at least 20 passes this season, sorted by total expected points added per play. Total EPA includes both passing and rushing production, and gives a full picture of a player’s offensive contribution. Kaepernick’s career numbers would put him 26th among quarterbacks this season, ahead of Matthew Stafford and Kirk Cousins — who are being paid a combined $50.5 million.

Most starting quarterbacks with NFL experience did indeed create value per play above what we might expect from Kaepernick, but Kaepernick’s worst season is still better than 26 percent of the quarterbacks who have attempted a pass in the NFL in 2018. Kaepernick may be a fringe starting NFL talent, but he is likely better than many of the quarterbacks who have seen playing time this season, including even Alex Smith.

It’s probable that Kaepernick could start for Washington and produce enough with his arm and his legs to salvage their playoff hopes. There remains the opportunity for Washington to sign him and find out for certain. Instead he continues to languish in free agency.

Check out our latest NFL predictions.

CORRECTION (Dec. 15, 2018, 11:45 a.m.): A previous headline on this story misspelled Colin Kaepernick’s name.