Yards per Play allowed by year

by acrollet on Nov 17, 2008 10:45 AM EST

Blitz mentioned that he was curious about ypp allowed in his post here, so I thought I'd write a quick little script to grab the numbers from pro-football-reference.com and make a couple graphs up. First, ypp allowed by year:

via farm4.static.flickr.com

As you can see, the overall trend is upward. Since 1979, only one team has allowed less than 4.0 ypp. (the 1991 eagles). I would be interested in knowing what happened near the end of the 60s to cause the ypp to drop so dramatically. (maryrose? :) )

via farm4.static.flickr.com

I also wanted to graph the overall defensive rank of the top team each year by yards per play allowed to see if that stat necessarily correlated to having a good defense. As you can see, the top team by ypp/a has only been outside of the top 5 in overall defense 11 times, so there seems to be a fairly good correlation.

You were correct Blitz, no defense has allowed less than 4.0 ypp since 1991. If the steelers keep it under 4.0 this year, it will be one more indication of how special this defense is...

At any rate, I hope I didn't steal your thunder - thought this would be fun to do.

UPDATE: ask and ye shall receive, at least if you're steelguy99 and I'm my lunch break...

via farm4.static.flickr.com

the upward trend since 1970 is very clear.

via farm4.static.flickr.com

less clear since 1990, but still clearly up, especially in the past few years.

Finally - Pittsburgh vs. the rest:

via farm4.static.flickr.com

Pittsburgh's graph does seem to track pretty well with our good years - note in particular the big dip in the 70s, and how 2006 spikes up compared to 2005 and 2007...

One more graph:

via farm4.static.flickr.com

YPP were actually better for pittsburgh in 1994 than 1995, interestingly enough - we still see a strong correlation between low ypp and successful seasons...

I definitely like the graphs/general nerdiness, dunno how much interest there is in general though :)

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Comments

This is solid stuff, quality work. Two “complaints”/requests:

1) The scale is too far out. It’s amusing to see time start so far back, but a more relevant graph I think would show these stats from 1970-current, and perhaps a separate timescale of 1990-current.

2) How have the steelers done on this scale? What are our yearly stats?

Awesome stuff though. I’d love to see more stat-graph-geek stuff up here, but maybe that’s just me.

by steelguy99 on Nov 17, 2008 11:18 AM EST reply actions

you got it

thanks for the suggestions – I had fun doing this, so if people have other things they’d like to see, I’ll try and put some more graphs up as time and interest allow. I’m not much good at thinking up what would be interesting to look at on my own ;)

by acrollet on Nov 17, 2008 1:50 PM EST up reply actions