Metrics that Matter: Just how good (or not) is Colin Kaepernick?

The QB has been the subject of much debate this offseason, both on-field and off. Scott Barrett looks at the on-field side.

| 4 weeks ago
Colin Kaepernick

(Harry How/Getty Images)

Metrics that Matter: Just how good (or not) is Colin Kaepernick?

(“Metrics that Matter” is a short feature that appears every weekday, highlighting a notable fantasy lesson to be learned from PFF’s advanced stats.)

I love finding interesting and unique stats. I could spend (and typically do) all day with my head buried in a number of different spreadsheets looking for the perfect stat to tell me what’s going on with a specific player. This was, of course, a main reason why I’m doing this series each weekday. Before I started writing this series, I would just post these different stats on twitter and sit back and watch the retweets fly in and debates unfold in my mentions. The most-debated player this offseason has been Colin Kaepernick: either he’s terrible and a locker room distraction and that’s why he’s unemployed or he’s a starter-level talent who is being blacklisted by the NFL due to political reasons.

I don’t care enough to debate this from a non-statistical level, but I do think I have some interesting statistics that can add fuel to either side’s fire.

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The Good: Throughout the history of the NFL, among all 186 quarterbacks to record at least 1,500 attempts throughout their careers, Colin Kaepernick ranks fifth-best in passing touchdown to interception ratio (72:30.)

Barrett Thursday

The Bad: Since the NFL merger (1970), among all 186 quarterbacks with at least 1,500 attempts throughout their careers, only David Carr has a worse Sack%+ (era-adjusted sack percentage) than Kaepernick. In the PFF era (2007-present), among all quarterbacks with 1,500 dropbacks, no quarterback has been sacked more often than Kaepernick, getting sacked on 8.3 percent of his dropbacks.

Since 2012, Kaepernick ranks 15th in passer rating of 30 quarterbacks to total at least 1,000 pass attempts. He also ranks third-best of these 30 quarterbacks in rushing yardage.

Kaepernick’s passer rating and touchdown to interception ratio are constantly being referenced by his proponents in arguments for why he’s unjustly unemployed. I’m not sure that’s right, however. Really, I think they’re highlighting a major flaw in traditional passing stats – that they neglect how often a quarterback is getting sacked. Sacks are major drive-killers, in that they result in the loss of a down and negative yardage.

Over the past 10 seasons, quarterbacks average a 61.7 passer rating when pressured and a passer rating of 95.0 when operating from a clean pocket. Rather than make a low-percentage throw, Kaepernick is choosing to take a sack. After looking at the data, I’m not sure that’s necessarily the right decision. Since 2009, only 6.7 percent of drives where a quarterback was sacked resulted in a touchdown. Either way, a sack, like an interception, is a negative quarterback play that should be factored into the equation when looking at a quarterback’s efficiency. One such quarterback stat does factor in sacks as a negative play: adjusted net yards per attempt . Over the past three seasons, among all 29 quarterbacks with at least 800 attempts over this span, Kaepernick ranks ahead of only Blake Bortles in adjusted net yards per attempt.

This isn’t just a product of Kaepernick’s offensive line, either. For perspective, last season, Kaerpernick was sacked on 8.7 percent of his dropbacks (sixth-highest), while Blaine Gabbert was much closer to league-average (5.6 percent) at 5.8 percent of his dropbacks. Last season, in Gabbert starts, the 49ers averaged 22.2 points per game with a negative-5.8-point differential. In Kaepernick starts, the 49ers averaged only 18.0 points per game and with a negative-12.9-point differential.

What does this mean for fantasy?

Not much.

Kaepernick is still unemployed and is unlikely to be named a starter wherever he lands. As for my own personal opinion on Kaepernick, I think he was once an average NFL starter, but has been playing at a backup-caliber level the past two seasons.

Among all 33 quarterbacks to play at least 500 snaps, Kaepernick was our worst-graded quarterback in 2015. In 2016, he ranked seventh-worst of 30 qualifying. Prior to that, he hovered around the NFL average.


Scott Barrett is our Senior Fantasy Analyst and one of the main hosts of our Fantasy Slant podcast.

  • Jr214

    Lol the picture chosen would be of him kneeling XD

  • jermz24

    “only David Carr has a worse Sack%+”

    Think you meant Derek Carr 😉

    • jermz24

      nvm, I read that wrong haha

    • Paul

      Derek carrs sack % is 3.9, which is considerabely less than league average. In fact its one of the best in NFL history.

      Regardless, sack data is a conflicted historical statistic, it wasnt tracked reliabely in the past, or even at all. Defensive players werent credited with sacks till 1982, and im not sure when individual qb stats tracked sacks and sack yardage lost. Most of the data now is estimations i believe.

  • Paul

    Im not going to pretend i read every PPF article, but thats the first mention of ANY/A ive seen here, Bravo. This was a very informative article. I dont get into the whole political aspect of sports, but if Kaepernick really is only a replacement level QB now, and teams feel the atmosphere around him is a distraction, then it does add perspective on why hes still unemployed.

  • Joel Brody

    Some good points there, but I think the picture is still incomplete. Yes, Kaep takes a ton of sacks, but his offensive line was terrible, despite a “for perspective” comparison with Blaine Gabbert. It doesn’t put in context who their opponents were during those starts. It also doesn’t specify what was a coverage sack, which there were many. Most of the time, Kaep would have 1.3 seconds and if the first read wasn’t there he was either sacked or had to take off running to avoid one. The 49ers’ center and guard play the last two years has to be dead last or close to dead last on pass protection.

    Also for perspective, Kaepernick’s top 3 targets last season were Garret Celek, Quinton Patton, and Jeremy Kerley. Please read that last sentence again. Um……..I’m not a fantasy or sports writer, but I don’t think those players are even replacement level starting caliber. Kaep has never had anything close to an elite offensive player, much less above average. An aging Frank Gore, Anquan Boldin, with a scrap heap of wasted Baalke draft picks.

    I’ll never be one to say Kaep was good the last couple years, but when you have poor coaching, poor line play, and the worst receiving core in the league bar none, only having 4 interceptions in 11 starts is pretty decent. I think 3 of those came in one game. QB rating is definitely an incomplete stat, but Kaepernick did have a higher QB rating than Cam Newton, Phillip Rivers, Eli Manning & Jameis Winston last season with all of those players having much better receiving talent and a much easier schedule (49ers had the no 1 strength of schedule).

    He’s a polarizing player and one that has regressed. His skill set was one to play ahead in games and needed players to separate to compliment his strong arm. No one in SF has played well the last two years offensively and it’s mainly been a downward slide of whatever was left from the Harbaugh era. I’m not saying Kaep deserves to be a starter, but definitely should be signed right now given the importance of the position and overall scarcity of starting experience players to at least compete in camp. Oh, he’s also 4-2 in the postseason.

  • juniorjohnson

    Kap lost his value when he lost his teammates respect (long before the knee BS).
    The QB has to be a leader and Kap isn’t a good leader. Doesn’t help that his playing style is limited.

  • itsdeplorablespideyman

    One other statistic to ponder: 1-10 last year, with the only win against the Rams.