STAT CLASS 101
Pass Defense vs. Pass Efficiency Defense
By Dave Hersh
NationalChamps.net Managing Editor
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October 19, 2004
You have probably noticed how very few statistics, when held to the light alone, genuinely expose a team's strengths/weaknesses. But if you poignantly align the right numbers and use simple logic, much is revealed as to why a team is performing a certain way. Trends definitely exist in some areas. And of course, decipher what you will. But we think we have a few cleaver, multi-faceted insider angles for how to break this information down. We compare/contrast certain basic vital statistics that, when focused together, can give a better understanding as to why a team does/doesn't do well.

Most important is this - what one set of stats means to one team, when mimicked, often leads to a totally different statistical and final outcome for another. In other words, there is no statistical prototype for success.

 

 

(AP Rank) TEAM Record

Pass Defense
Rank
(a)

Pass Effic.
Defense Rank
(b)

Run Defense
Rank
(c)

Total Defense
Rank
(d)

N.C.State 4-2

1

6

22

1

Alabama 5-2

2

1

39

3

San Jose State 2-3

3

18

117

92#

(6) Wisconsin 7-0

4

3

8

2

Houston 1-5

5

62*

108

63#

(4) Miami 5-0

6

4

40

11

(10) Georgia 5-1

7

66*

25

4

(23) Va. Tech 5-2

8

8

31

7

(31) Missouri 4-2

9

12

32

8

(8) Texas 5-1

10

9

69

29

(3) Auburn 7-0

11

16

20

5

Fresno St. 3-2

12

2

56

21

Nevada 3-4

13

47*

99

62#

(38) Ga. Tech 4-2

14

17

41

16

Connecticut 4-2

15

23

57

22

(18) LSU 4-2

16

24

19

9

(34) S. Carolina 5-2

17

5

27

14

Miss. St. 1-5

18

102*

87

56

Utah State 2-5

19

96*

109

81#

Navy 5-1

20

53*

68

37

Southern Miss. 4-1

21

10

91

59

Maryland 3-3

22

31

54

28

Oregon 3-3

23

37

46

25

Boston College 4-2

24

13

14

12

Tulsa 1-5

25

51

102

74#

Washington 1-5

26

71*

88

61#

Kansas State 2-4

27

90*

67

39

Kentucky 1-5

28

77*

106

84#

Penn State 2-4

28 (tie)

27

43

26

UCLA 4-2

30

43

116

105#

 

HOW TO USE - What we have done for this week's Stat Class 101 is a bit different. Instead of taking the Top 30 teams by weekly national ranking, we list above the top 30 in declining order for pass defense. The left column is the teams' name and record, with appropriate national ranking (AP) if needed in parenthesis. The next column over (a) is the given team's pass defense ranking. After that is (b) the team's pass efficiency defensive rank, with (c) the run defense, and then finally (d) its total defensive rank in the far right column.

First thing to grasp is how the pass "efficiency" defense is different from just pass defense. Pass defense is based solely on a team's yardage totals. The pass defense ranking is figured for how many yards per game are allowed through opponents' passing efforts. Pass efficiency defense takes not only their yardage, but pass completion percentages, both INT total and percentage of INTs thrown, TD total and rate, yards per attempt and yards per completion into account to then give an overall rating. Just like yardage, the lower your opponent's pass efficiency number, the better you are doing. But unlike stopping just yardage, if the other guy is mistake-free and can score via aerial assault, you are likely going to lose. Really, you can survive a 50-yard pass play that only gets them to your 35, but there is no "recovery room" from an 11-yard scoring strike set up by 12 good runs. It is good when your opponents are less efficient, even if they get a few extra yards.

A team can have disparaging ranks in (a) and (b) (the first two columns) for different reasons. First, look and see how many teams, nine, have a 30-or more rank difference between (a) and (b) (teams marked by an asterisk - *). Notice how only one, Georgia, is actually a ranked team. Most importantly, the No.10 Bulldogs rank 25th (c) for run stopping (108 yards per game and 2.9 yards per carry), meaning opponents have to go to the air early and often. The end result is a strong total defensive rank (d) of 4th, but their marginal pass efficiency defense (b) of 66th still means one loss. That loss (to Tennessee 10/9/04) was highlighted by the Vol's small passing yardage total (150 yards), but two catches were for TDs and none were for INTs - efficient enough for a 19-14 Tennessee victory. Sean Jones, where are you?

Of the remaining eight (*) teams, the highest run stopping ranks (c) are 67th for Kansas State and 68th for Navy, which still makes their overall defenses rank (d) 39th and 37th, respectively. KSU struggles at 2-4, but they also bring the wood each and every week in their tough conference, and Navy has but one loss. But then for the rest, a high run stopping ranking (c) coupled with a bottom-half (ranking lower than 60th out of all 117 I-A teams) pass efficiency defense equals, at best, Mississippi State's 56th total defense and their 1-5 record. The Bulldogs may not bend that much, but, evidently, they are often broken. In other words…pass defense yardage is important, but not as important as pass efficiency defense and run stopping efforts in producing both total defense and wins. If your opponent can run all over you, then your pass defense number/ranking can be low yet you still lose.

Still, if you stop passing yardage (a), you are well on your way toward a strong overall defense (d). Notice how only eight (#) of the top 30 pass defenses (a) rank in the bottom half for total defense (d). But of them, only UCLA is winning through it all, and that must be due to both their strong pass (a) and pass efficiency (b) defensive rankings. If the Bruins ever improved their second-to-worst run stopping rank (c), they would be right there with USC and Cal this year. (The only way for UCLA to beat USC December 4th is if they can first stop Reggie Bush, and any extra men in the box to do that will be exploited through eventual passing success.) The rest of them (#) rank no higher than 88th for run stopping (c). Again, conclude this - if you can't initially stop the run, neither your pass defense (a) nor your pass efficiency defense (b) will provide enough total defense (d) to keep you winning. As long as your opponent is efficient when throwing, he need not get gads of yards in order to beat you.

Systematically, the teams with no marks, either a (*) or a (#), seem to be doing well. Penn State is the only non-marked squad with a losing record, but the Big Ten is no picnic for a team like PSU struggling with identity. The Nittany Lions were one TD from possibly upsetting Purdue, which means they would now be 3-3 and would fit this paradigm.

Bottom Line - Balance on defense is most important. So, no matter how high one's pass stopping ranking may be, in the end, keeping foes from passing yards (a) alone means nothing. Also, a team can still win having either a weak pass efficiency defense (b) or a weak run stopping game (c), but not both.

 

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