Daily Archives: May 25, 2015

A little more on stopping the run as a means of generating turnovers

I brought up Manny Diaz’ philosophy last week and a couple of bloggers of a more statistical bent than I explored the topic as well.

At Football Study Hall, Chad Peltier did a little regression analysis on the subject and found that Diaz wasn’t full of shit.

There’s enough evidence to reject the null hypothesis that there isn’t a relationship between defensive rushing S&P+ and turnovers gained. Rush defense doesn’t explain the whole variation in the data on turnovers gained (r squared is .14), but the two variables do seem to be related in a non-random way (at the 95% confidence level).

In short, the stats do seem to support Diaz’s argument that a defense should work on stopping the run first and foremost for more turnovers.

And today at Team Speed Kills, David Wunderlich does a little statistical exploration, finds some correlation, but wonders if there’s more to it than what Diaz suggests.

But wait a second. Let’s apply a different truism, this one from Football Outsiders: “You run when you win, not win when you run.” As Aaron Schatz explained it:

There are exceptions, usually when the opponent is strong in every area except run defense… [h]owever, in general, winning teams have a lot of carries because their running backs are running out the clock at the end of wins, not because they are running wild early in games.

Apply this to a defensive context, and winning teams will defend more passes than runs. Certainly it’s possible to have a great defense that doesn’t win a lot of games—see Auburn and Tennessee in 2008, or Florida in 2013—and it’s possible to win a lot of games with a terrible defense—see 2011 Baylor, which won 10 games despite being 113th in scoring defense. There are always exceptions, and that’s why these correlations are in the +/- 0.300 to 0.400 range rather than, say, the +/- 0.700 to 0.800 range.

Still, teams that win a lot of games usually have good defenses. We should also expect that good defenses will force a lot of turnovers. We’re now stuck in the correlation vs. causation trap. Does strength at stopping the run cause a team to generate more turnovers? Or does simply being a good defense cause that unit to both stop the run and generate more turnovers?

I’ve always believed that context matters, so I would be stupid to dismiss David’s qualifiers there.  But it’s worth mentioning that Louisiana Tech, while leading the nation in turnovers last season, finished 9-5.  Take that for what it’s worth.

In the meantime, let’s see what Diaz does in his second tour of duty at Mississippi State.  As David concludes,

One thing I can say for sure is this: when you share a division with Nick Saban, Bret Bielema, Gus Malzahn, and Les Miles, focusing on stopping the run isn’t a bad plan.



Filed under Stats Geek!, Strategery And Mechanics

COA as a bullshit detector

As we watch the ongoing race to pay, Andy Schwarz makes a wonderful point.

To critics of amateurism such as economist Andy Schwarz, the ease with which schools added stipends undercuts the argument made by some schools in 2011 that such stipends could lead schools to eliminate unprofitable sports.

“The rhetoric that you hear a business say before a fixed price changes is just that: rhetoric. The actions that you’re seeing now are more telling,” said Schwarz, who uses clinical economic terms when discussing college sports that would make some school officials cringe.

“This is a great natural experiment. We’re getting to see change in an economic environment and see how firms react,” Schwarz said of the new stipends. “We’re learning a ton about the real preferences of schools with where they decide to put their money.”

Not that it’ll stop anyone from making up stuff about the next bridge too far.


Filed under It's Just Bidness

Which offensive line coaches have best protected their quarterbacks?

Over at coachingsearch.com, they’ve taken the time to look at which offenses over the past three seasons have generated the best ratio of passes attempted per sack allowed.  Now, while I think the question in my header, which is posed in the post, is a bit over broad in assessing the cause/reason, it’s still interesting to look at sack rates, particularly in Georgia’s case.

Will Friend didn’t make the list of top fifteen.  Here’s a breakdown of the numbers from 2012-4:

  • 2014:  17 sacks allowed; 322 passing attempts; 18.9 pps
  • 2013:  22 sacks allowed; 459 passing attempts; 20.9 pps
  • 2012:  27 sacks allowed; 399 passing attempts; 14.8 pps

A couple of things there worth noting.  One, while so many of us have harped on Aaron Murray’s turnovers over his career, we seemed to have missed out on the insane level of improvement in sack avoidance he made in his last season.  (And, remember, that was with right tackle play that was inconsistent, to say the least.)  Two, while Mason was very good in the turnover department, there was a drop off in the pass per sack rate last season.  And that was with a much bigger reliance on the running game and a far more stable offensive line that what Georgia had in Murray’s last season.

The overall three-year numbers?  66 sacks allowed in 1180 passing attempts, leading to a 17.9 pps ratio.  Again, not that close to the numbers on the chart posted at the link.  It’ll be interesting to see where that goes this season, with a new QB, offensive coordinator and line coach.


Filed under Georgia Football, Stats Geek!

“Once you start your senior year of high school, you should be able to sign at any time.”

For once, I have come not to bury the genius, but to praise him.

It’s Johnson who wants to bury something, in this case, National Signing Day.

“The schools have their 85 scholarships, and you can sign no more than 25 in a year. When you sign your limit, you’re through. If you sign a kid and he doesn’t qualify, you lose it for that year. We put the onus back on the kids with better grades and better students, and we stop all the craziness of the hat shows, soft commits, decommits and all that.”

A grumpy clock is right twice a day and all that, but it’s hard to fault his logic here:

But Johnson says opening things up would also make the schools more cautious when handing out those offers to begin with, citing the ridiculous amount of offers high schoolers in Georgia get early in the process.

“It would also slow the schools down,” Johnson said. “We sit here in Georgia, where there are a ton of great high school players. We’ll have everybody come in here, offer 200 kids, and if a kid wants to commit, ‘It wasn’t a committable offer.’ I don’t know what that is. It would just clean it up.

If a kid said he was committed, you hand him the papers. If he didn’t sign, you knew he wasn’t committed. The same thing on the schools. If the kid went in, and they said, ‘You’ve got an offer,’ and the kid wants to sign, (he’d) call their bluff as well. I just think it would clean the whole thing up and put the onus back on the good students and kids who want to do it right.”

What would really be interesting to watch under his scenario is what would happen to all the offers made to high school juniors once they embarked on their senior season.  Pipe dream, I know.


Filed under Recruiting

The further adventures of run the damned ball, Bobo.

Some really solid stuff from Ian Boyd here about what sort of offenses force teams to make solo tackles more than others.

As you might suspect, teams that deploy spread attacks tend to force more solo tackles than others.  But check out this chart of the ten most efficient offenses in 2014:

S&P Rank Team % Solo Tackles Solo Tackle % Rank
1 Ohio State 72.5% 84
2 Alabama 72.9% 82
3 Oregon 72.4% 86
4 Georgia Tech 80.5% 22
5 Auburn 75% 66
6 Mississippi State 67.8% 11
7 Oklahoma 73.3% 76
8 Georgia 69.4% 105
9 Baylor 83.1% 12
10 Michigan State 70.7% 100

Two out of ten were really good at forcing solo tackles, and Georgia Tech was above average in that regard.  The rest were anywhere from subpar to genuinely poor at it.

Now ask yourself why that’s the case.  Well, actually, Boyd’s gone ahead and answered that question.

Well this puzzle is simple enough to solve, there are more defenders around the line of scrimmage then there are in the flats or downfield. If there are more defenders around on a running play then it’s going to be easier for the defense to get multiple people to the ball carrier to help bring him down.

Why are their more defenders there? Because defensive coordinators look at the S&P rankings and determine that the teams that can run the ball effectively are often the most difficult to defend. So they always ensure that there are players around the box that can limit damage from the run game. You’ll notice that the efficient running teams that rank high in S&P were also generally good at punishing this defensive response with the passing game.

Everyone wants their passing game to revolve around getting their athletes in one-on-one match-ups in space where they become hard to tackle, whether you are a pro-style power run team or a four-wide Air Raid spread squad. However, the teams that are killing are the ones that set this up with the run.

As a general rule, solo tackles occur most frequently from the passing game or from bad running attacks that put the running back in positions where he can’t evade a single tackler and is brought down before he can get up to speed.

Georgia is the most extreme case on that list:  5th in rushing S&P+; 105th in solo tackle percentage.  Teams were doing exactly what so many defensive geniuses on the Internet advocate – loading up the box to force Georgia to beat them throwing the ball – and were still getting killed on the ground in spite of this tactic.

Which should tell you a couple of things about the Dawgs’ offense.  First, Todd Gurley and Nick Chubb are a couple of ridiculously talented running backs.  Second,  deploying the play action pass should be like taking candy from a baby. There’s always going to be at least one receiver running around with single coverage.  Georgia just needs to find the quarterback best suited to take advantage of that.


Filed under Georgia Football, Stats Geek!, Strategery And Mechanics

A Memorial Day thought

Today, more than any other day, it’s worth reminding ourselves not to rely on the nobility of the sacrifices made by those serving in the armed forces to excuse the lack of wisdom of our elected officials who often put them in harm’s way for questionable purposes.  And when it comes to downplaying the honor of our troops because of questionable politics, vice versa.

To the former, I say thanks, sincerely.


Filed under Uncategorized