There's been a fair amount of discussion recently regarding Cal's defense, including much citing of statistics, and while the discussions have been very interesting, I feel like we might be approaching some of these statistics in the wrong way. The usage of statistics seems to fall mostly into the following two categories, both of which are problematic:
1. Looking at statistics in a vacuum - e.g. "Wazzou passed for 350 yards against us, so our secondary is doing badly".
--> Hypothetically, Wazzou could be passing for 400+ yards against everyone else. We know that this isn't the case, but the point is that the frame of reference is somewhat arbitrary/subjective.
2. Looking at statistics in terms of Pac-10 ranking - e.g. "Cal is second in the Pac-10 in points per game".
--> Hypothetically, the next eight Pac-10 teams could just have really terrible offenses. Also, this fails to account at all for strength of schedule, which is definitely relevant to a team's statistics.
For the purposes of this fanpost, I decided to use a slightly different method of evaluating Cal's defense: comparing opponents' performance against us to their average performance this season. In other words, instead of looking at whether our defense performed better or worse than average against each opponent, I'm looking at whether our defense made opposing offenses perform better or worse than they usually do. This isn't a particularly original idea, and it has its own flaws (again, it doesn't take schedule into account at all), but it has the virtue of demonstrating in what manner opposing offenses are able to perform well against us, compared to their other performances.
The index below is the ratio of how an opposing offense performed against Cal to how they normally perform, i.e. a higher index means they did better against us than they usually do; a lower index means that they did worse against us than they usually do.
|3rd Down %||0.4||0.24||0.6|
|Red Zone %||0.87||1||1.15|
(This game was the reverse of all the others in terms of rushing/passing indices, but Maryland is a horrible team, so I wouldn't read too much into it.)
|3rd Down %||34.86||33.33||0.96|
|Red Zone %||0.83||1||1.2|
|3rd Down %||31.05||46.67||1.5|
|Red Zone %||0.91||1||1.1|
(This is one of those cases where the stats don't show how horrible the beat-down was...also Oregon has been beating a lot of other teams down as well, which probably explains the relatively low indices.)
|3rd Down %||32.8||40||1.22|
|Red Zone %||87.3||100||1.15|
|3rd Down %||29.25||31.25||1.07|
|Red Zone %||80.95||100||1.24|
|3rd Down %||22.04||35.29||1.6|
|Red Zone %||73.53||50||0.68|
(Those passing numbers are kind of embarrassing...)
|3rd Down %||29||0.33||0.01|
|Red Zone %||86.21||0.75||0.01|
Finally, here are the index "averages" - note that these are averaged across games, not across plays (i.e. so the average YPA would be the average of each game's YPA, not the average of all attempts over the season).
|3rd Down %||0.99|
|Red Zone %||0.93|
Again, this is a pretty unscientific way of looking at the numbers - but I think it provides some context to the discussion.
Thoughts? Criticisms? Suggestions? Honkings?