Downs And Success: An Attempt At A Different View

Submitted by LSAClassOf2000 on August 1st, 2013 at 1:56 PM

DOWNS AND SUCCESS: AN ATTEMPT AT A DIFFERENT VIEW

So, I asked myself a question the other day. Many of us probably assume – as I do admittedly – that sustained success on third down conversions has something of a cascade effect in that drives are sustained and the chances of scoring and, by extension, winning are drastically increased. The question I had is this – in the numbers, how strong is the relationship between some of the statistics involved in possibly sustaining drives?

I decided to go five seasons back to see if we could at least begin to see relationships. Clearly, the farther we go back, the clearer the picture could become, but this is simply an initial delve into this particular subject, so this will do. I figured that if I did begin to see things, an expanded view might be in order in the future.

As I normally do, to keep it somewhat topical for the board, I confined this to the Big Ten, although I do have some data from all of Division I. That will decrease the strength of any conclusion perhaps, but as I mentioned, this was more about scratching the surface.  

Like other diaries, this is mainly about confirming relationships that many of us already may intuitively surmise.

SOME BASIC BREAKDOWNS:

I did something here that I normally do in these situations and come up with some arbitrary way to divide win totals and then create a table to see if there was a basic relationship 3rdand 4thdown conversions and relative success (this includes 2008-2012 data for the Big Ten):

 

WIN TOTAL

3RD DOWN ATTEMPTS

3RD DOWN CONVERSIONS

4TH DOWN ATTEMPTS

4TH DOWN CONVERSIONS

3RD DOWN CONV. PCT.

4TH DOWN CONV. PCT.

11 OR MORE

1913

861

131

76

45.01%

58.02%

10

1136

490

69

41

43.13%

59.42%

9

1123

464

83

42

41.32%

50.60%

8

941

413

95

54

43.89%

56.84%

7

1859

761

160

83

40.94%

51.88%

6

1090

425

111

58

38.99%

52.25%

5

674

282

64

23

41.84%

35.94%

4

912

334

108

53

36.62%

49.07%

3 OR LESS

1220

430

144

73

35.25%

50.69%

 

So, on a most basic level, we can see a couple things – there is some relationship between your relative record and your success at converting third downs, but there doesn’t seem to be any significant relationship between relative record and 4thdown conversions, or at least not nearly as significant as the one that may exist on third downs.

Here is some very basic data for first downs, including the number of first downs for each group and the percentage relative to total offensive plays:

 

WIN TOTAL

FIRST DOWNS

TOTAL OFFENSIVE PLAYS

% OF FIRST DOWNS / TOTAL PLAYS

11 OR MORE

3032

9614

31.54%

10

1603

5524

29.02%

9

1574

5408

29.11%

8

1349

4517

29.86%

7

2348

9071

25.88%

6

1487

5253

28.31%

5

988

3374

29.28%

4

1143

4231

27.01%

3 OR LESS

1499

5658

26.49%

 

Again, on a basic level, there is some relationship here – the better the relative record, the better you probably are at getting first downs. Not Earth-shattering stuff at all, right? It just happens to be somewhere in the numbers as well, that’s all.

How strong are those relationships? Well, the R-value for the relationship between 3rddown conversion percentage and winning percentage for the Big Ten sample is 0.542, so there is a mild relationship there, with “mild” perhaps being an operative word here. For the relationship between 4thdown conversion percentage and win percentage, that value drops to 0.277, so there is not nearly the same linkage between the two sets of numbers.

It may be worth noting, however, that for all of Division I, over an expanded eight years of data that I collected, the R-value between 3rddown conversion percentage and win percentage is only slightly higher, sitting at 0.556. However, the R-value for 4thdown conversion percentage in the same relationship is noticeably higher – 0.355. That could be the sample size, of course. It could also be that this relationship might be somewhat different in other conferences or historically for other teams.

WHAT YOU KNEW ANYWAY, BACKED WITH NUMBERS:

I decided to look at some different relationships after the previous exercise produced a less-than-thrilling cursory look at the matter. The obvious thing that does come out of these many possible correlations is the relationship between 3rddown conversion percentage and the percentage of plays that are first downs. The R-value in this case is 0.806, indicating a fairly good correlation, showing you in statistical form something you already knew all along – the more successful you are at converting third downs, the more first downs you will get.  Now, however, you can tell your friends just how closely tied the two things are. More directly, the R-value for 3rddown conversion percentage and first down totals is 0.771, so there’s the same thing in a slightly different set of variables.

WHAT MAY NOT BE SO APPARENT:

On third down conversions from 2008-2012 (the five years here is to accommodate restrictions on finding first down data ) the Big Ten actually averaged 41.04%, with Michigan State and Minnesota actually being the worst at it overall. Neither team reached that number once in five years. Indiana only did so once, as did Purdue. Michigan stayed above that average three times, but of course, Michigan has the dubious distinction of having the worst percentage in any given year in that time period – 27.27% in 2008. Indiana managed 27.65% that same year.

For all of Division I in the past eight seasons ,  here were the least successful  teams on third down:

 

Year

Name

3rd-down Attempts

3rd-down Conversions

Pct

4th-down Attempts

4th-down Conversions

Pct

2010

Vanderbilt

171

46

26.90%

19

4

21.05%

2008

Washington St.

179

48

26.82%

18

9

50.00%

2005

Ohio

155

41

26.45%

5

0

0.00%

2007

Army

175

46

26.29%

26

10

38.46%

2010

San Jose St.

172

45

26.16%

13

7

53.85%

2005

North Carolina St.

165

42

25.45%

16

7

43.75%

2006

Temple

155

38

24.52%

23

4

17.39%

2007

Florida Int'l

173

42

24.28%

28

9

32.14%

2009

Washington St.

168

40

23.81%

15

7

46.67%

2006

Florida Int'l

166

39

23.49%

24

7

29.17%

 

For some contrast, here are the ten best:

 

Year

Name

3rd-down Attempts

3rd-down Conversions

Pct

4th-down Attempts

4th-down Conversions

Pct

2006

Hawaii

133

77

57.89%

20

8

40.00%

2010

Stanford

172

99

57.56%

16

11

68.75%

2008

Tulsa

193

110

56.99%

21

9

42.86%

2006

Brigham Young

168

94

55.95%

11

6

54.55%

2008

BYU

176

98

55.68%

10

7

70.00%

2009

BYU

169

94

55.62%

13

5

38.46%

2005

Southern California

167

92

55.09%

30

18

60.00%

2008

Texas

173

95

54.91%

16

13

81.25%

2012

Texas A&M

195

107

54.87%

12

7

58.33%

2011

Wisconsin

170

93

54.71%

10

7

70.00%

 

 

BACK TO THE FOURTH DOWN THING:

The only meaningful way to see if there was anything actually going on with fourth downs, I felt I should try to break this admittedly small sample up by team, so again, I used the Big Ten.

One thing that I can say here for all of Division I across eight seasons of data is that the overall success rate for all attempts on 4thdown made in that period id 50.59%, so in essence, it is an even-money proposition to go for it on 4thdown and the numbers bear that out as well.

The Big Ten, from 2008-2012, averaged 52.12% on 4thdown conversions. Iowa and Indiana actually happen to be the least successful in the last five years at converting on 4thdown – Iowa has never hit the average, and Indiana rose above the average only once in four years. Michigan is in a wide field of teams that have converted better than 52.12% in three of the past five years.

As for the whole of Division I in the past eight seasons, here are the ten worst instances of 4thdown conversion success:

 

Year

Name

3rd-down Attempts

3rd-down Conversions

Pct

4th-down Attempts

4th-down Conversions

Pct

2010

Troy

200

86

43.00%

13

2

15.38%

2006

Colorado

159

53

33.33%

13

2

15.38%

2011

Kent St.

190

54

28.42%

20

3

15.00%

2009

Virginia

177

60

33.90%

14

2

14.29%

2005

Stanford

146

48

32.88%

7

1

14.29%

2010

Memphis

164

53

32.32%

7

1

14.29%

2012

Connecticut

177

64

36.16%

7

1

14.29%

2012

Kentucky

178

71

39.89%

22

3

13.64%

2009

Hawaii

149

67

44.97%

17

2

11.76%

2009

UAB

141

52

36.88%

10

0

0.00%

 

Again, for contrast, the best on fourth down:

 

Year

Name

3rd-down Attempts

3rd-down Conversions

Pct

4th-down Attempts

4th-down Conversions

Pct

2011

Notre Dame

174

81

46.55%

6

6

100.00%

2005

Penn St.

166

73

43.98%

6

6

100.00%

2011

Stanford

175

92

52.57%

12

11

91.67%

2010

LSU

183

70

38.25%

12

11

91.67%

2011

TCU

169

88

52.07%

11

9

81.82%

2010

Illinois

177

72

40.68%

11

9

81.82%

2008

Texas

173

95

54.91%

16

13

81.25%

2011

Air Force

181

85

46.96%

32

26

81.25%

2007

LSU

223

104

46.64%

16

13

81.25%

2006

Boise St.

154

67

43.51%

21

17

80.95%

 

PUTTING THIS STUFF ON GRAPHS:

This is what the relationship (or lack thereof) for win percentage, third and fourth down conversion percentage and the relative percentage of plays which were first downs looked like over five years for the Big Ten:

 photo WisconsinDownsPct_zps119eaffc.png  photo OhioStDownsPct_zpsc76f0e55.png  photo PurdueDownsPct_zpsab80d22b.png  photo NorthwesternDownsPct_zpsf5de475b.png  photo PennStDownsPct_zps8d9ea428.png  photo NebraskaDownsPct_zps8fc0212c.png  photo MinnesotaDownsPct_zps1b0b3ac2.png  photo IowaDownsPct_zpsfddf4599.png  photo MichiganStDownsPct_zps359b0685.png  photo IndianaDownsPct_zpscb1a6da9.png  photo MichiganDownsPct_zpse4c421d7.png  photo IllinoisDownsPct_zps0a894909.png

TL;DR CONCLUSION:

So, other than some obvious relationships, I was admittedly a little disappointed that I didn’t find much more approaching the issue from this direction. In the future, I will probably try to go at this from a different angle - what that might be is up for debate. The sample for the conference is admittedly small, so there is that. Perhaps I am missing something which warrants a more careful examination, and not being an expert, that’s entirely possible.  If I have done anything here, it is confirm one or two things statistically perhaps that most of us knew anyway, and I suppose I can count this as a minor victory. Rather than rail against the “eye test” in this case, I seem to have confirmed an instance where it works.

OBLIGATORY:

Comments

docwhoblocked

August 1st, 2013 at 10:11 PM ^

They also look to have one of the highest attempt rates on 4th.  Wonder what is going on there? There is evidence that you should always go for it on 4th down especially any time you are across the 50.  The yardage gained by punting is rarely worth the lost opportunity to score if you do convert the 4th down in your opponents territory.  

TennBlue

August 2nd, 2013 at 1:33 AM ^

for a comparison, as that also depends on the defense and other stuff that has nothing to do with the offense.  A team can convert 3rd downs all afternoon and still lose if their defense is bad.

 

You might find a better correlation with points scored, or touchdowns specifically, or maybe an inverse correlation with field goals (maybe teams that don't convert 3rd downs tend to kick FGs more).

 

There's more to winning than just scoring points, so incorporating defensive performance would be necessary (and some special teams).  Converting 3rd downs would be a component of predicting scoring, while that could then be combined with the other game aspects to get a correlation with winning.

LSAClassOf2000

August 2nd, 2013 at 6:06 AM ^

This is a timely comment because I was discussing it with someone last night. Limiting it to 3rd down perhaps and then incorporating performance on both sides of the ball might be more useful, or as you mention, correlate it to certain aspects of scoring offense. That's probably what the next step here would be. I was actually hoping someone would help fill in the hole I figured was there (this was a shot in the dark with some of the available data admittedly) - thanks for the suggestions. 

EDIT: I calculated the 3rd down conversion differential (offense-defense, in this case) for each Division I team and correlated this to both win percentage and PPG and came out with R-values of 0.752 and 0.659 resepctively. I think that is at least part of the adjustment I was looking for the other day but couldn't quite figure out. Finding help like this is one of the reason I love this place. Seriously.

Case in point...

 photo 3rdDownDiffMichigan_zps102ead6a.png

 

Here's the link in the event that's too small...

 photo 3rdDownDiffMichigan_zps102ead6a.png

Blarvey

August 2nd, 2013 at 7:05 PM ^

Good stuff!

I am curious if there were any teams had a consistently low winning pct. yet a consistently high conversion differential. It would seem unsustainable except for an academy or a defense so bad they had unusually high numbers of first and second down conversions.