Advice

Using Analytics to Project Carson Wentz and Jared Goff

Recently RotoViz debutante Chris Hatcher wrote an interesting piece about quarterback ball velocity and how that translates into one metric of passing success at the NFL level. I decided to take his work a step further and used logistic regression to model QB success. There are multiple ways to define QB success. One might be with fantasy stats. Another might be raw totals. The metric Chris used was whether or not a QB threw for an AYA of 7.0 or higher for at least one season in his career, while also starting 8+ games in said season. I will also use this as my criteria for success. I like this criteria for a few reasons:
  1. The data was easy to get1
  2. It leaves out rushing statistics, so we’re focusing only on passing
  3. It incorporates touchdowns and interceptions along with yards
  4. It strongly correlates with NFL win percent
  5. It doesn’t matter how long a QB plays, if they reach the threshold, they usually do so early in their careers. This is important because you might expect the criteria to bias against players with only one or two seasons under their belt. But both Marcus Mariota and Jameis Winston met the threshold in their first year. I tested number of seasons in the NFL against probability of success, and found there was no correlation (p=0.8). This held true even when controlling for other variables, such as draft position.
The data set I used for ball velocity is the same data set Chris used – combine data on every thrower since 2008 as recorded by Ben Allbright. I then grabbed other combine results and player stats to use when training and testing my model. In the few cases where combine data wasn’t available, I used pro-day numbers and on one occasion (for John David Booty) I imputed his 3-cone time from other metrics. In all, there are 94 quarterbacks from 2008-2015 with velocity data. Of these 94 QBs, 73 played at least one snap at the NFL level (77.7 percent). Breaking that down further, only 15 of the 73 QBs that played met the success criteria that Chris established in his article. In other words, most QBs fail. There are plenty of quarterbacks who either didn’t throw at the combine, or at least didn’t have the ball velocity stat recorded. As such, this analysis only applies to QBs who had a ball velocity recorded.
  1. It was right there in Chris’ article…yeah, I took a shortcut  (back)

Subscribe to the best value in fantasy sports

You're all out of free reads for now and subscribing is the only way to make sure you don't ever miss an article.

By RotoDoc | @RotoDoc | Archive

Comments   Add comment