There are too many solutions to the topic of what has recently gone wrong with the Florida defense in a single piece. However, the truth remains that UF hasn’t had a strong defense since 2019, which was five years ago as of this autumn.
Dividing defense into two categories—efficiency and explosiveness—is one way to make things simpler. Efficiency refers to the defense’s down-to-down performance. The frequency and magnitude of big plays that a defense permits determines how explosive they are.
Success rate for efficiency and projected points added on successful plays for explosiveness are the metrics I’ll be utilizing to gauge these. To make sure we’re both on the same page, let’s take a time to clarify what those are. By the way, the statistics I’m utilizing are from College Football Data.
The proportion of all plays that are considered “successful” is known as the success rate. A play must acquire at least 50% of the yards needed to go on first down, at least 70% of the yards needed to go on second down, and 100% of the yards needed to go on third or fourth down in order to be considered successful. If you want to view a fast explanation of this standard definition, I did a video on it over ten years ago. It’s been around for a while.
Although success rate is not ideal, it is frequently employed because it is superior to many other options. For example, it penalizes a team for getting eight yards on third and 15, but gives credit to a team for gaining two yards on third and 1. One limitation of this approach is that it does not take into consideration the situation in which a coach chooses to employ four-down thinking, meaning that instead of attempting to convert on third down, he aims to move the ball far enough to facilitate fourth down. Though he certainly doesn’t do it enough to make a significant impact on the numbers over the course of a season, Billy Napier enjoys applying four-down reasoning.
Average expected points added (EPA) on plays that are successful as judged by success rate is the explosiveness metric. The fundamental tenet of EPA is that yards gained are the best way to score, with yards close to the opponent’s end zone being worth more than those farther away. It determines how many theoretical points a play gains and gives yards point values. The offensive team will gain more offensive points (EPA) with a ten-yard gain from the opponent’s 20-yard line than from their own 20.
In case you skipped over it all, defenses must be strong on a down-by-down basis, not allow too many huge plays, and not allow too long large plays when they do eventually allow them. Both the explosiveness measure and the efficiency measure (success rate) should have smaller values.
I looked up Florida’s defensive success rate and explosiveness over the last 20 seasons in order to gain a clear understanding. When the scoring margin is more than 38 points in the second quarter, more than 28 points in the third, or more than 22 points in the fourth, I opted to remove garbage time. That removes a ton of inaccurate info.
Plotted against the left Y-axis is the blue line, which represents efficiency/success rate (notice that it doesn’t start at 0% to make things simpler to perceive); plotted against the right Y-axis is explosiveness.
Historically, Florida has maintained a success percentage below 40%, which is commendable because 42-43% is around the national average for any given year. Apart from a single glitch in 2007, everything was going well. The success rate then skyrocketed for three years in 2020.
Maybe more intriguing is the explosiveness line. It has been rising consistently since 2008, when it reached a low. That includes periods when defensive brains with track records (Muschamp, Collins) and others with similar records (Grantham, Toney, Armstrong) were in control. In the spread era, offenses have had the upper hand thanks to plays like RPOs that take advantage of the college illegal-man-downfield loophole and high-tempo attacks that generally result in more big plays.
This chart makes it very easy to determine what went well and poorly in the previous year. The permitted non-garbage time success rate fell to 37.9%, the lowest level since 36.0% in 2016. That was more than decent, but it’s not like Charlie Strong did it.
Simultaneously, the explosiveness metric reached a record-breaking level of 1.58. Not seldom, there have been poor one-year leaps from 2013 to 2014 and from 2016 to 2017, albeit from lower baselines. It’s not even entirely off the trend line, which is a troubling trend line, to be clear. But it’s a lot worse than LSU’s 1.38, and after the season, Brian Kelly sacked almost every member of his defensive staff. It’s also worse than USC’s 1.35, which resulted in the dismissal of their DC. It is impossible to minimize that figure.
It wasn’t just me who saw the difference between the explosiveness and efficiency defenses last year. Others have since picked up the drumming, although I think the hosts of the Gator Nation Football Podcast were the first to do so.
I’m attempting to provide an example of why I believe that insight is important to emphasize here. The 2023 defense’s success rate was comparable to many of the previous units that Gator supporters had praised. Still, the permitted explosiveness was remarkably high.
With as many as four or five true freshmen playing defense at once for UF, it is best to assume that the high explosiveness allowed was a result of their youth. All those men have gained valuable experience already, and by Week 1, they will have completed another preseason camp, a summer of playbook study, and a spring practice session.
Employees have grounds to believe that more development is possible. Because of Justus Boone’s injury during the preseason, there was almost no pass rush, which gave quarterbacks more time to search the field for big plays. Remember this: the defense gave up a pitiful average of 1.82 EPA on the relatively few successful plays, but only 28% of passing downs (2nd & 7 or more, 3rd/4th & 5 or more) were successful. Thankfully, there’s a lot more depth to the edges this year.
The linebacking corps also had a great deal of difficulty following Shemar James’s injury. Myles Graham, a new signee, and transfer Grayson Howard provide strength and talent that were absent from James’ squad last season.
Ultimately, maybe Ron Roberts’ expertise and insight may help bring that explosiveness figure back down. The success rate figures show that Austin Armstrong made the right call most of the time. Simply put, he was incorrect far too frequently and seriously when it came to pivotal moments.
If Florida can maintain its level of performance from the previous season, their defense will be in excellent position. All it needs to do is quit crumbling so spectacularly and frequently. They can afford to make that compromise, even if it means losing one or two percentage points of success rate in order to reduce the number of huge plays. Their efficiency from the previous season was respectable.
Though not completely unpleasant, the bad last year was so much worse than the good that it was difficult to see the good. Even though the staff has a difficult task ahead of them in bringing the explosiveness factor back down to manageable levels, hopefully you can now understand where the good was.
