I was reflecting on our win yesterday, and how crucial it was that our defense held IU to field goals on several drives that went deep into our territory.  I got to thinking about red zone percentage numbers - the way everyone calculates them, a field goal is worth the same as a touchdown.  Doesn't make much sense, does it?  If the other team's going to score, you'd much rather have a team that allows three points per trip inside the 20 than one that allows six.  So, I went to the NCAA website and grabbed the redzone defense numbers, and calculated a sort of weighted percentage.  Basically it's this:

weighted percentage = (red zone TDs + 0.5 * red zone FGs) / total red zone trips

Yes, I know that a TD usually winds up being worth 7 points, but a 2:1 value for TDs vs. FGs seemed like a good starting point.  Why did I bother doing this?  Well, mostly just to see if numbers justified my perception that regardless of how the defense as a whole plays, it's really tightened up inside the 20s.  How do we measure up?  Well, I put the whole Big 10 on a...

Chart:

School	Drives	Red zone %	Rank	Weighted red zone %	Weighted rank	PPT
Penn State	8	63%	7	44%	3	2.88
Indiana	10	70%	20	55%	17	3.80
Michigan	15	73%	27	57%	21	3.87
Iowa	7	100%	111(t)	64%	42	4.14
Minnesota	12	83%	63	67%	51	4.50
Purdue	16	81%	58	75%	89	5.19
Illinois	10	90%	93	80%	106	5.50
Northwestern	15	87%	79	80 %	108	5.53
Wisconsin	13	92 %	102	81 %	110	5.46
Michigan State	12	100 %	111(t)	88 %	113	5.92
Ohio State	5	100 %	111(t)	90 %	118	6.40

Note - "Red zone %" and "Rank" are the defensive numbers straight from the NCAA website, and the weighted numbers are mine.

So what does this mean?

It's still early in the season, but we can start to see a few things. 

• First, I was right - Michigan is near the top of the conference, and has done a pretty good job of keeping folks out of the endzone when they get inside the 20. 
• Holy hell, MSU.  If we get in the red zone, we should get points - probably 6 of them. 
• Iowa's interesting - every red zone trip, they've given up a score.  However, they've done a damn god job of limiting people to field goals.  (Admittedly, that's on only 7 drives.)
• Penn State's been pretty darn good, allowing a TD on only 25% of their red zone trips.
• Before you start gloating about OSU being at the bottom of the list, look at the number of drives.  That's right, they're allowing an average of 1.25 red zone drives per game.  Of course, they gave up touchdowns on almost every trip, but small sample size blah blah.

Other random things of interest:

• Virginia Tech checks in at #4 nationally, allowing TDs on only 4 of their 17 defensive red zone trips.  They must put something in the water in Blacksburg, cause that's ridiculous.
• Oklahoma and Florida are #2 and 5, respectively.  It's just not fair to put defenses that tough opposite offenses with the kind of firepower they have (assuming their QBs are healthy, anyway.)

Thoughts?  I just ran these numbers for fun, but is this something I should revisit every couple weeks?

EDIT - I added in the "PPT" column.  This is the "points per red zone trip" metric discussed in the comments, and it's what I used for my red zone offense post here.  This didn't change the rankings too much - if I reranked based on the new metric, Wisconsin would leapfrog Northwestern and Illinois by a slim margin, but that's it.  Also of interest is that using the PPT metric, OSU gets jumped by Arizona and Louisiana-Monroe, leaving the Bucks dead last in NCAA D1A.  That makes me smile inside, even if it is just an artifact of a small sample size.