Photo by Eric Francis
Nebraska Football

Scheme vs. Skill: An Exploration of Big Plays

August 9, 2017
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Lane Kiffin is famous, or infamous, for many things in his 20-ish years as a football coach. One of the stranger sagas – which is saying something with Kiffin – is when he briefly became known as the offensive coordinator who signaled touchdowns before they happened at Alabama in 2014.

He did it against Auburn on a 75-yard touchdown pass to Amari Cooper. Internet video of that seems to have sadly died with Vine. But there’s video of the second time Kiffin did it, which happened just a week later in the SEC Championship Game against Missouri.



At a press conference before the Sugar Bowl that season, Kiffin tried to downplay his explosive-play premonitions. Somewhat. (Emphasis mine.)

“I do that 30 times a game. They only show it when it works,” he said. “A lot of times I just, I’m not, I don’t even know I’m doing it really. It’s just in my head that they’re in this coverage and so there’s an excitement because you’re calling plays to get a defense.

“If we get this defense, we’re going to score. As long as we execute it and make the throw. And so there’s times that you can tell what they’re in so that you know, okay, this is going to work.”


It’s not always that simple and that’s the mystery of explosive plays. Every coach I’ve ever talked to tracks them in some way. They’re important. From 2011 to 2016, drives with an explosive play resulted in points 74.1 percent of the time across college football. Nebraska’s numbers over that span are even better – 77.7 percent of offensive drives with an explosive play resulted in points and 72.1 percent of defensive drives resulted in points for the opponent.

To put it another way: “The main thing that produces points is explosive plays,” defensive coordinator Bob Diaco said in the spring.

If explosive plays are that valuable, how does a team set about getting or preventing more of them? How much of it is scheme – what Kiffin’s talking about when he gets the coverage he wants – and how much of it is skill of individual players?

“Players make explosive plays,” Maryland head coach DJ Durkin told me at Big Ten media days in Chicago last month. “Yeah, you can create some of those through scheme, but there’s a lot of great coaches out there. It happens to all of us. Someone makes a mistake. Most of the time things are pretty well covered. It’s a guy going to make a play, it’s a guy making a tackle, it’s a guy beating a guy deep. That’s the game. That’s why recruiting is so important.”

We’re probably never going to arrive at a true number on this topic – say, explosive plays are 20 percent scheme, 80 percent skill – but that doesn’t mean we can’t take a look at every big play of the Mike Riley era at Nebraska, both on offense and defense, to see what it might tell us.



To find a way into the numbers here I created some half-arbitrary, wholly unofficial scenarios to help chop things up. Only half-arbitrary because I started from the concept of standard and passing downs, which comes from success rate, a football stat that assigns a winner and loser (offense or defense) for every play based on if the offense stays on schedule. The average success rate for college football between 2011 and 2016 was 41.6 percent.

The other stat you need to know is explosive-plays percentage, which is simply gains of 20-plus yards divided by total plays ran or defended. Between 2011 and 2016, teams gave up or hit for a 20-yard gain on 6.5 percent of plays. They’re rare, but they change games.

With that in mind, these are the inelegantly named scenarios we’ll be examining: Neutral Ground, Roll the Dice, Proceed with Caution and Thoughts-and-Prayers. Here’s what they mean and what’s happening at Nebraska in each:

NEUTRAL GROUND (NG)

Scenario: Any first down
Percent of All Plays (National Average): 44.1
Success Rate: 42.9
Explosive-Plays Percentage: 6.5

All first downs are standard downs, doesn’t matter if it’s first-and-25. This is football’s neutral ground. Theoretically the offense might have a slight edge. It can gamble if it wants and risk ending up in second-and-10, it can call something it thinks will get 5 yards and stay ahead of the chains. The defense has to react to either approach. But the fact that the explosive-play percentage on first down is the same as on all downs is a solid indication that this is “straight-up football.” And Diaco calls it a “50-50 down.”

Huskers Offense: In two years under Mike Riley, Nebraska’s explosive-plays percentage on first down was 6.8 percent and its success rate 44 percent. Translation: The Huskers have been slightly more efficient than explosive on first down. Nebraska has played things pretty close to the vest here, running 69.1 percent of the time on first down compared to 54.3 percent of all downs the last two seasons.

Huskers Defense: Nebraska gave up an explosive play 8 percent of the time on first down in two years under defensive coordinator Mark Banker. Most of that damage was done in 2015. Teams threw the ball 46.3 percent of the time against a porous pass defense that year (a high rate), and had an explosive-play percentage of 10.7. The latter number came back down to good in 2016 (5.4 percent), but taking the Banker era at Nebraska as a whole the Huskers just weren’t very good at defending against big plays as you’ll continue to see.

ROLL THE DICE (RtD)

Scenario: Second-and-4 or less
Percent of All Plays: 7.3
Success Rate: 55.1
Explosive-Plays Percentage: 4.3

If there was a scenario that could entice offensive coordinators to take a shot downfield or otherwise chase an explosive play, it had to be second-and-short. The stakes seem to be the lowest here. If a team’s deep ball off of play-action is incomplete or its double reverse gets stopped at the line, it is still in a manageable third-and-4. So scheme it up. Do the Kiffin thing. At least that’s what I thought might happen, but the numbers show that explosive plays drop quite a bit in this specific scenario, which makes its own sort of sense. The success rate in this scenario is high so the offense has a clear edge and football coaches as a whole are pretty conservative. It looks like offensive coordinators are content to keep that edge with plays that are designed to stay on schedule rather than aiming big. And that makes Nebraska’s performance in this scenario particularly interesting.

Huskers Offense: Nebraska’s explosive-plays percentage here is nearly double the national average in the Riley era* – 8.5 percent – and its success rate (60.4) is up there, too. If you were defending the Huskers in second-and-short the past two years, you had to be ready for them to take a shot and more than 80 percent of the RtD explosive plays came via the pass. Now, the sample size with this scenario is pretty small, so it’s possible the Huskers’ numbers are noisy at this point. (Tim Beck’s number as offensive coordinator in the Big Ten at Nebraska, for example, was dead average.) But assuming they’re not too noisy, Nebraska has the profile of an offense that will go against type and test defenses when the odds are on its side. Also interesting: The two explosive plays in Bryan Reimer’s short career have come on RtD downs.

Huskers Defense: Nebraska’s best scenario in terms of limiting the explosive play under Banker, which fits the overall puzzle of a defense that struggled in that regard. The Huskers gave up an explosive play 3.3 percent of the time on RtD downs. Most teams are going to bust the least when opposing offenses are playing conservative most of the time. Bo Pelini’s Big Ten defenses (2011-14) were even better with an explosive-plays percentage of 2.8.

PROCEED WITH CAUTION (PwC)

Scenario: Second-and-5 to third-and-5
Percent of All Plays: 34.8
Success Rate: 40.4
Explosive Plays Percentage: 6.0

This one is sort of a hodgepodge, hence the wishy-washy name. On all but the extreme ends of the span, we’re talking about passing downs on second down and standard downs on third down. In general, the offense should still be able to use most of its playbook when you take the scenario as a whole, but the defense, based on the lower success rate and explosive-plays percentage, has a slight edge. Without watching every explosive play and making a subjective determination, it’s going to be hard to break this category into neat scheme-or-skill categories.

Huskers Offense: After putting up some big numbers on RtD downs, Nebraska has been basically as good as the average offense in college football on PwC downs – 43.3 percent success rate, 6.1 percent explosive plays. More than 75 percent of Nebraska’s explosive plays on PwC downs have come via the pass, which, given that the defense should have a slight edge, probably says less about scheme and more about a Husker passing game that, even with its limitations elsewhere, was pretty good at hitting for gains of 20-plus over the past two years.

Huskers Defense: Sort of a strange mix here again. Nebraska was efficient on PwC downs with a 35.6 percent success rate, but a little more likely than the average defense to give up an explosive play (7.0 percent). So, again, we’re sort of just left to realize what we already knew: Nebraska struggled so mightily to defend against big plays in 2015 that it’s still clouding things a year later when the Huskers actually got better in 2016.

THOUGHTS-AND-PRAYERS (T&P)

Scenario: Third-and-6 or greater, all fourth downs
Percent of All Plays: 13.8
Success Rate: 33.0
Explosive-Plays Percentage: 9.0

So named because all you can do for the offense facing a third-and-9, or a defense that gives up a 28-yard post in the same scenario, is send your thoughts and prayers. The defense should win here, plain and simple. OK, maybe the occasional fourth-and-short is advantage offense, but for the most part these are situations that favor the defense.  And it’s another scenario that defied my hypothesis. I assumed that with a heavy edge to the defense you’d see decreased explosive plays, but the opposite is actually happening. T&P downs are volatile downs. The defense will win most of the time, but with offenses knowing they need, for example, 10 yards they have to aim high. Therefore when the defense loses, it can lose big.

Huskers Offense: Riley-era Nebraska has been better than average in this category, too, in terms of explosiveness and especially efficiency. Considering that the majority of the time these are pure passing downs, it again speaks to a well-conceived passing game. But it also speaks well, I think, to the “skill” part of the equation. To hit for 20-plus yards on a third-and-long, when the defense knows what an offense needs, a team is going to need players to win some one-on-one battles. The fact that Jordan Westerkamp, Alonzo Moore, Brandon Reilly and Cethan Carter are all getting shots at the NFL probably isn’t unrelated.

Huskers Defense: One of the two scenarios the Blackshirts “won” under Banker. It wasn’t by a lot. Nebraska’s explosive-plays percentage on T&P downs was 8.2 percent, but that’s slightly better than average. If the Huskers relative success in RtD scenarios could be attributed largely to offensive indifference, the success here, just like on offense, probably says a little something about talent level. The core-four combo of Nathan Gerry, Aaron Williams, Joshua Kalu and Chris Jones were capable of winning their share of battles.



Aaron Babcock Defensive coordinator Bob Diaco during spring practice in 2017.
It’s probably not wise to draw too many hard-and-fast conclusions here. This was more of a “let’s see what’s happening here” exercise, so it might lend itself more to theories.

I have some of those.

While I won’t speculate on the specific percentages yet, the numbers indicate to me that explosive plays are probably more about skill (or talent) than scheme. Maybe a lot more. That’s my theory based on the fact that when offenses have the most opportunity to pursue big plays they’ve actually gone down, and when a defenses should be the most prepared to defend them the percentages go up. I side with Durkin, not Kiffin, which is probably true for any sort of scenario you can imagine now that I think of it. (Note: I’m sure Kiffin isn’t firmly “it’s all about scheme,” but every story needs an antagonist and it doesn’t seem to be a role he hates.)

Also, there’s a passing bias when you use 20 yards as the cutoff point for what constitutes an explosive play. The vast majority of runs, not including sacks as rushing attempts, are never going to reach that threshold (just 4.1 percent in 2016). It’s hard to scheme a 25-yard run, so you could say that every explosive run requires some degree of skill. At some point, a ball carrier’s ability is going to have to be what gets him the extra 10, 12 or 15 yards, which means the numbers above might underestimate the role skill plays.

Nebraska, however, presents a complicated case heading into 2017. If we classify Neutral Ground and Proceed with Caution downs as close to 50-50 scenarios, the Huskers’ offense has been about as good as the next team in terms of efficiency and explosiveness. But on Roll the Dice downs, which might shade towards “scheme,” Nebraska’s explosiveness takes a huge jump. On Thoughts-and-Prayers downs, the Huskers’ explosiveness is also better than average, which I think says good things about Nebraska’s talent level, particularly in the passing game. That’s a well-structured offense with a more-than-adequate talent level, which is a good combo to have.

Normally I’d say that the greatest growth opportunity in terms of explosiveness for an offense like that would be to continue to increase the “skill” part of the equation with better recruiting. Given that Nebraska has shown some proficiency in “scheme” situations, however, getting the right trigger man in at quarterback – which everyone assumes Nebraska has now – could also offer more gains than would be typical.

Defensively, we can probably toss the last two years. At least that was the hope with hiring Diaco, and he presents an interesting challenge to the theory that explosive plays are more about skill than scheme. I included his Notre Dame numbers for the years I had them (2011-13) on the defensive chart above as a reference point, but they’re really, really good. The Irish didn’t give up an explosive play on more than 6 percent of plays in any of the scenarios. Diaco’s numbers at Connecticut, working with a lesser talent level than at Notre Dame and a necessary big-picture focus as the head coach, weren’t quite as stellar, but they were still pretty good. The Huskies ranked in the top 35 nationally in two of Diaco’s three years there. I think it’s safe to say that limiting big plays is a trait of his defense.

And that indicates that scheme has to be something of a factor here because talent levels are always fluctuating, yet the “no-crease defense” has worked at various stops. I mean, just look at the way he talked about personnel on Tuesday.

“In some instances, even though you might have a starter, he might be more appropriate on a 50-50 down, first and second down, than on third down-and-3 or more, third down-and-4 or more, or as a drive starts to pile and you get to play eight, can a player still play better than the next man in? So even in the players that you can see as stalwarts, there is still a deep evaluation happening based on putting the game together.”

Diaco doesn’t like to give much away, but get him talking about the intricacies of defense and you’ll get some gems like above. He’s talking about an intense amount of planning, “putting the game together,” and while the stated goal might not be “we’re doing all this to avoid giving up any plays of 20-plus yards,” all of that specialization has had that effect in the past.

Explosive plays win games, particularly when you combine them with turnovers. And like turnovers, it’s a little tough to pin down how you “coach” that. Unlike turnovers, which are effectively random, coaches do seem to have at least some influence over explosive plays, however.

How much? It’s hard to say. I said I wasn’t going to speculate, but now I’m reversing field. If you wanted to ballpark it by assigning basic weights based on the designations above – say 50-percent skill on NG and PwC, 75-percent scheme on RtD and 75-percent skill on T&P – you end up with explosive plays at 53.5-percent skill across college football. That feels low to me, but using the same criteria Nebraska’s offense during the Riley era benefitted a little bit from scheme (52.4-percent skill) and the Huskers’ defense was about average (53.3-percent skill).

What’s it mean for Nebraska in 2017? We’ll find out soon enough, but here’s my last theory: It looks pretty good on paper. Even if we assume most explosive plays come down to skill, Nebraska’s offensive scheme, at least as I defined it, has shown the ability to produce them at an increased rate. And Diaco’s past defenses, if they’re any indication of what’s in store in Lincoln, are perhaps one of the best examples out there of consistently winning one of college football’s most important battles.

* CORRECTION: This story originally mentioned an explosive-plays percentage from 2011 to 2016, when it should have said "the Riley era." It has been updated to reflect that change.
 
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