Oklahoma Sooners Football: An analytical evaluation of changing defensive coordinators

I generally balk at the idea of midseason coordinator changes like the one Oklahoma Sooners coach Lincoln Riley made to oust Mike Stoops. They smack of panic, and my best guess is that they rarely work out for the better.

Of course, the head coaches who make those kinds of moves usually have their asses firmly affixed to smoldering hot seats. That’s what makes the decision to do this midway through the year unique.

Riley has seen this kind of move work in the past as part of Texas Tech’s coaching staff under Mike Leach. In fact, OU’s new interim coordinator, Ruffin McNeill, was thrust into that same role with the Red Raiders in 2007. It worked so well for Tech that Leach elevated McNeill to full-time coordinator at the end of the year, with McNeill holding the job for two more seasons before East Carolina hired him as its head coach in 2010.

This time, it appears as though McNeill will be working very closely with newly installed outside linebackers coach Bob Diaco on running the defense. Will it work as well for Riley as it did for Leach a decade ago?

What do the numbers say?

I reached out to my friend Dave Bartoo, a consultant with Matrix Analytical Solutions, for his take. Bartoo has data and evaluations on more than 350 college football defensive coordinators dating back to the 2008 season. From a numbers standpoint, he says OU’s coach made a no-brainer call.

“If he was going to make a change, then Lincoln Riley made a solid decision,” Bartoo said. “He has put the program in a situation with a higher potential ceiling.”

Bartoo noted that according to his metrics, the Sooners are currently the top team in the country in offensive scoring efficiency, same as the 2017 team. Defensively, however, OU has fallen from 56th overall in scoring efficiency last season to 88th in 2018.

If the coaching staff can simply keep the defense from getting worse for the rest of the year, that might enable the Sooners to duplicate last season’s run to the Big 12 championship game, according to Bartoo. The open date this week made now the right time for a move.

“This could not have been set up any better,” said Bartoo. “The offense should still be good enough to win games, and the coaches get six weeks to turn the defense around.”

About that turnaround…

Does OU have the right people in place to reinvigorate the D? McNeill grades out as a B- defensive coordinator based on his stint at Texas Tech, according to Bartoo (Stoops’ overall grade: D-).

Looking back at McNeill’s time in Lubbock, advanced stats show the Red Raiders improved rapidly on defense under his leadership. Tech finished the season prior to McNeill taking over, 2006, ranked 46th nationally in Defensive S&P+. In the next three years, the Red Raiders came in 31st, 24th and 19th. OU fans might recall Tech’s defense stealing the Sooners’ lunch money as part of a 41-13 beatdown in ‘09.

Bartoo is particularly enthusiastic about Diaco’s involvement, even after his one disastrous season with Nebraska in 2017. Diaco earned an overall B+ for his combined six seasons as a defensive coordinator at Cincinnati, Notre Dame and NU.

“Diaco has had some really good years,” Bartoo said. “He has a high ceiling. Peak Diaco is excellent.”

Diaco’s resume includes a stellar four-year run at ND. The Fighting Irish finished the 2009 season ranked 39th in the country in Defensive S&P+. Once Diaco joined the program with head coach Brian Kelly in 2010, ND finished 11th or better in three of his four seasons in South Bend. That included overseeing the unit that led the Irish to an undefeated regular season a national championship game appearance in 2012. (Ironically, the Sooners experienced Diaco’s defensive handiwork that year in a crushing 30-13 defeat at the hands of the Irish.)

In terms of a permanent hire in the future, Bartoo cautions that defensive coordinators generally grade out differently based on the volume of plays their defenses face. “Some great coordinators see their defenses fall apart in games where their defenses are on the field for about 85 plays or more,” he said.

You have to take that into account in a league such as the Big 12, where uptempo offenses are the norm. It’s one of the major concerns with Diaco, whose defenses have seen their performances erode in games in which they’re on the field for 80-plus plays.

Marrying the Sooners’ high-powered offense with an uptempo-tested defensive coordinator should pay off quickly, though, according to Bartoo.

“If Riley gets this hire right, OU becomes a legitimate, consistent contender for the national title,” Bartoo said.