Denver run defense 2017 could be better than 2015

If you look back at the stats, the Denver Broncos had a good to great run defense from 2012 to 2015. See below.

The 2016 run defense regressed horribly - giving up a full yard more per carry than in 2015. Much has been made of how good the 2017 run defense has been so far. We know how the run defense finished in the previous five seasons, but I wanted to see how it started and compare that to this year. So below is a table of rushing yards allowed by year in games 1-4 going back to 2012 (removing QB kneel-downs).

As you can see, even in 2015 when we had one of the best run defenses in the NFL this century, we were not playing all that well in the first 4 games that year. That year we allowed three runs of 20 or more (48 yd TD to Adrian Peterson, 34 yard run by Jamaal Charles and a 20 yard run by Justin Forsett) in the first four games. This year we have allowed exactly one run of 20 or more (21 yards to Melvin Gordon) and it was on the first run of the season against us. To see how we compare graphically here is a histogram of the runs allowed by distance against us in the first four games going back to 2012. Focus on the thick blue and orange lines

I made the lines for 2015 and 2017 larger to pick them out more easily. The 2015 run defense was actually quite good in the first four games with the exception of those three long runs I mentioned earlier. That 2015 had a host of 1 and 3 yard runs against it in the first four games.

Interestingly, the 2017 run D appears to be getting a host of 0 and 2 yard runs against. 48 of the 81 runs against us so far this season have resulted in a gain of two yards or less (59%). That is called a stuffed run or a win for the defense (if it’s not in a 1 or 2 yards needed for the first or for a TD situation). So our 2017 run defense is winning roughly two out of three times when our opponents try to run the ball - and these aren’t cell-phone salesman trying to run the ball against us either. Marshawn Lynch, LeSean McCoy, Melvin Gordon and Ezekiel Elliot have a combined 12 Pro-Bowl selections and four 1st team All-Pro selections between them. We’re shutting down elite running backs.

As you can see in the table above, the run defense is allowing 2.56 yards per carry (I take QB kneel-downs out). Leaving the three kneel-downs in, we have allowed 203 rushing yards on 84 carries - 2.42 yards per carry. The best that any team has done since the merger in a full season is allow 2.70 ypc. That was the 2000 Ravens who allowed 970 yards on 361 carries. In case you are wondering, they held their first four opponents to 186 yards on 89 carries (2.09 ypc). Here’s how our 2015 and our 2017 run defenses compare to that D in the first four games

Note that I changed the color for the 2015 DEN run D in games 1-4 to green to make it easier to see with the purple Ravens line. The 2017 run D does not have as many TFLs in the first four games as the 2000 Ravens had, but we are very comparable in terms of the number of runs for 0 and two yards that we are allowing. That 2000 Ravens run D had a stuffed% of 63% through 4 games which is a little better than our 2017 run D.

So our 2015 run D was one of the best this century, but how did it stack up to the 2000 Ravens run D? Below is a full season histogram of runs allowed comparing the two defenses.

Our 2015 run D was amazing, but it was not as good as the 2000 Ravens when it came to stuffing the run. For the season 57% of runs against the 2000 Ravens resulted in a gain of 2 yards or less. For the 2015 Broncos that value was 52% - still amazing, but not “best ever” level.

If the 2017 Denver run defense can keep up their current pace they will be in the conversation with the 2000 Ravens as one of the best, if not the best, run defenses in the history of the NFL (since the merger).