Some Of The Ups And Downs Of The Defense In 2013

Submitted by LSAClassOf2000 on December 10th, 2013 at 11:39 AM

DEFENSIVE SUMMARY FOR 2013

In this particular diary, we shall give the defense a similar treatment to the offense, which was dissected in a diary last week.

One thing that I will say right now, however, is that when you look at the numbers in isolation, you wouldn’t necessarily have too much to really criticize, at least not terribly harshly. There were a couple “off” performances if you will, but many good ones as well. On a yards allowed basis, per the NCAA site, Michigan would be 38thin the FBS, which is perhaps not what we would have hoped at the beginning of the season, but in my mind, being in the upper third on the list means you’re at minimum above average to good in most of the more important metrics. If nothing else, games were kept manageable.

SUMMARY DATA:

TOTAL PASSING

2736

TOTAL RUSHING

1674

TOTAL YARDS

4410

 

 

AVG. PASSING

228.00

AVG. RUSHING

139.50

AVG. YARDS

367.50

 

 

AVG. COMP. %

54.45%

AVG. YDS PER COMP.

12.80

AVG. YDS PER ATT.

6.80

AVG. YDS PER CARRY

3.76

AVG. NO. PLAYS

70

AVG. YDS PER PLAY

5.21

The above table is the summary breakdown of performance on defense. As mentioned, we were 38thoverall, but that includes being ranked 28thin rushing defense and 60thin passing defense. One thing about these numbers  - and it will be discussed a little more in-depth later – is that they are also good for 33rdin pass efficiency defense.

WHAT WE ALLOWED:

This graph below is similar to one that was in the offensive summary, showing you yards per play allowed with yards per rush and yards per completion overlaid onto it. You may note the relatively close relationship between yards per play and yards per completion. I believe it ties back to the difference between pass defense and pass efficiency defense and how the two can be quite different for teams.

 photo 2013DefensiveSummary1_zps753bdca3.png

So, what you see here is nothing new – there were two notably subpar performances against Indiana and Ohio State. On a yards per play basis, there were some notably good performances against Central Michigan, Northwestern and Connecticut. There was a lot in between, but mainly very good work overall by the Michigan defense in limiting the success of opponents enough to keep games within reach.

The relationship between passing yards allowed and overall yards allowed will look somewhat similar. Actually, here is the normalized graph for rushing, passing and the total.

 photo 2013DefensiveSummary7_zps68e32401.png

Save for the Ohio State game, they tend to trail each other. Our success on defense was very much predicated on our success stopping teams in the air.

POINTS PER PLAY AND ITS UPS AND DOWNS:

There is some debate about the overall usefulness of points per play as a metric, but I happen to think it gives a rather good 10,000-foot view of how hard you’re making a team work to score against you. Here is what that looks like for our defense this year:

 photo 2013DefensiveSummary3_zps061a8971.png

The trendline doesn’t say much given the R-value, but it doesn’t tell a terrible tale overall (again, two games stand out as no so great performances). Indeed, we had eight games where this number was 0.40 or less, so we weren’t doing a bad job of making teams work to score.

PASSING EFFICIENCY:

The disparity between measuring pass defense in terms of mere yards allowed versus efficiency, which takes into consideration things like touchdown and interception percentages, has always been an interesting talking point, I think. Here is what passing yards versus passing efficiency looked like for Michigan’s defense:

 photo 2013DefensiveSummary8_zps459ea4d1.png

Again, the trend tells a story you probably knew. Throughout the season, teams threw less, but the strikes were increasingly more surgical in their nature. The R-values are again low here, but there is a vague tendency in both cases.  It could have something to do with the styles of the passing offenses we faced, but what it does say is that we were doing a good job of making opposing QBs look relatively inefficient most of the time, but when they connected, it was probably a play that stung.

THE CONTRIBUTIONS ON THE GROUND AND IN THE AIR:

The next two graphs show the relative contributions of passing and rushing to yards allowed. In summary, as the season wore on, teams began to throw a little less and run a little more in relative terms, but relating it back to the id of efficiency, it shows how much the plays that were successful meant perhaps to the outcome of the game.

 photo 2013DefensiveSummary6_zps9ec951a0.png  photo 2013DefensiveSummary5_zps35a67040.png

Here is the frequency of rushing and passing against Michigan:

 photo 2013DefensiveSummary2_zps1f6785aa.png

CONCLUSION:

Again, this is more or less presented without comment as many of my diaries are, but overall, the defense does deserve credit for what it managed to achieve all the same this year.

 

Comments

AC1997

December 10th, 2013 at 4:38 PM ^

This is all wonderful data.  Is there any way you can put some of it into context to help understand how our D compares to either other teams, past Michigan teams, etc.?  

tybert

December 10th, 2013 at 9:43 PM ^

1. Two years ago, someone showed the 2010 vs. 2011 statistical D performance using number of "big plays" given up - specifically, they had number of plays 11-20 yds, 21-30 yds, 31-40 yds, etc. The number of big plays across the board, in all yardage histograms was staggering from '10 to '11

It would be interesting to see the 2011 vs. 2013 big play comparison. Having been at a number of games, the breakdown on big plays was obvious (Indiana for sure, and Ohio State - MSU and PSU also got some late on us)

2. 3rd down conversion rate was 38.3% allowed (51st overall) for 2013. I'll have to research the 2011 numbers, but remember it was lower, like under 30%. This year, I know I was frustrated how many times we got burnt on 3rd and 7+ on passing plays. Miller hit Devin Smith for 53 yd TD on 3rd and 10, thanks to Furman being out of position as safety.

The discussions earlier this year on LB drops and safety play seem to support our sense that the D under-performed, but maybe it wasn't as bad as our memories make us think.

3. 3rd down conversion by game. Note: Ohio was only 3 for 8, because they made so much on 1st and 2nd downs. Other BAD games of note: MSU 9 of 18, IU 8 of 14, ND 8 of 15, Akron 9 of 18, Minn 8 of 15. 

We won 4 of those 5 even when the D allowed 50+% - partly because the offense played well, and partly because we got hurt mostly on a few drives (Minn, Akron, etc.).

Overall - grade wise I'd give this D a B-minus. It kept us in games while the O struggled, including keeping us at 16-6 score in MSU.