Shotgun Spratling | USCfootball.com

An advanced analytics look at the Sam Darnold effect

Advanced analytics are becoming increasingly popular in college football. Over the next several weeks we will take a look at different USC story lines using advanced analytics.

In these advanced stats pieces we’ll be using Bill Connelly’s S&P+, which examines what Connelly deems to be the five factors of success for a college football team. These five factors are: the offense’s ability to create explosive plays, gain first downs, evaluate the ability of the offense dependent on field position, ability to score once it gets inside the 40 yard line, and to limit turnovers. On the defensive side S&P+ uses all of those ideas above, but the opposite.  Let’s dive in!

USC is 4-3 the halfway point of the season and it looks like Clay Helton may be fending off those calling for his head - for now. A lot of this has been attributed to the change in quarterback from Max Browne to Sam Darnold. Two popular arguments are “Well, Max never really got a chance” or, “The schedule softened up a bit since Sam took over.” Let’s take a look at these statements individually.

“Max never got a chance”

Max got a chance, but the offense simply didn’t move with him at the helm. The national average for Yards-Per-Play (YPP) is 5.45. Below is a simple bar chart showing the yards per play for the offensive performance for each game, the best game Max Browne had was against Stanford with 5.19 YPP. The more damning performance really is the one against Utah State, currently the 58th rated defense per S&P+. In the game against Utah State, the offense averaged 4.76 YPP, a similar performance to what Air Force put up against the Aggies, but inferior to both of the performances from Boise State and Colorado State. For Browne individually, it’s important to look at Yards-Per-Attempt (YPA) when examining a QB’s skill set and the throws he’s willing to make. In his time as a starter Browne only averaged 4.8 YPA and only 5.38 YPA specifically against Utah State. One last thing to keep in mind is that the national average for YPA is approximate 6.6, so Browne’s performance, unfortunately for him, was decidedly below average. In Darnold’s appearance in the Utah State game he averaged 8.86 YPA in a limited sample of seven attempts. One thing to keep in mind when you look at YPA for quarterbacks, the numbers account for negative plays like sacks and lost yardage on runs for a quarterback. This is unique to Bill Connelly’s methodology where he feels a sack should be counted against a pass attempt rather than a rush attempt which we tend to agree with. This differs from ESPN’s for example because their stats account for sacks as rushing attempts.

The first game for Darnold (#4 on the chart) as a starter, on the road at Rice-Eccles against the 23rd best defense in S&P+, resulted in a 2.5 YPP jump for the offense as a whole.  To compare, let’s look at how college football’s best offense fared against a team closest to Utah. Against Duke, the 33rd ranked team in the defensive S&P+, the Louisville Cardinals averaged 7.39 yards per play. Darnold already looks like a special player at QB.


“The schedule’s softened up a bit since Sam took over”

Looking at the S&P+ numbers for the defenses that Darnold has faced, the redshirt freshman has played Utah with the 23rd best defense, ASU at 104th, Colorado at 27th, and Arizona at 102nd. The Arizona schools are truly awful at defense, but the performances against Utah and Colorado should be celebrated. The reason being is that Darnold, while leading USC’s offense, is responsible for Utah’s worst defensive performance of the season (39th percentile) and Colorado’s second worst (46% barely 2nd though 45% is 1st vs Oregon). The percentiles are relative to each defense’s performance to the season based on all performances.

Lastly, let’s look at Darnold vs Cody Kessler. Darnold is averaging an impressive 8.7 YPA, while Kessler averaged 6.8 YPA. Darnold is also completing 66.7% of his passes where Kessler completed 66.8% last season. Darnold is completing virtually the same percentage of passes while pushing the ball downfield more on lower percentage throws. The reason those numbers are important is the following tweet by Dan Rubenstien of SB Nation.

https://twitter.com/DanRubenstein/status/786998403913936897

 Coach Clay Helton could be rightfully criticized for probably not starting Sam Darnold right away, but he should be praised for making the change when he did, this offense is better for it.

(Stats via footballstudyhall)

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Saman Djabbari graduated from USC in 2008 and is a weekly contributor to uscfootball.com and co-host of the Traveler Hates Thursdays' podcast. You can follow him on Twitter at @samandjabbari.


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