There were three teams last season that overwhelmingly relied on one running back, and all three made the playoffs: the Chiefs with Kareem Hunt, the Steelers with Le’Veon Bell, and the Rams with Todd Gurley. Given the success the Jaguars had after drafting Leonard Fournette on the heels of the Cowboys revival after drafting Ezekiel Elliott, you might think that — combined with the sentence above — relying on one running back is trendy again.
But that’s the difference between anecdotes and data. The Bears were the fourth most “rely on one RB” team, and Chicago went 5-11. The Browns went 0-16 and were very Isaiah Crowell-heavy. And the Colts were the same with Frank Gore and it brought them a 4-12 record.
On the other side, both the Eagles and Patriots had three running backs finish with between 60 and 180 carries, and those teams met in the Super Bowl. The Seahawks didn’t exactly have a rushing game that you would envy, but no Seattle running back had even 70 carries and the team had a winning record.
Last year, I discussed the idea of rushing concentration indices. Let’s use Hunt as an example. He rushed for 1,327 yards, and all Chiefs running backs rushed for 1,462 yards. So Hunt rushed for 91% of all rushing yards produced by Kansas City running backs. To get the Chiefs RB rushing concentration index, we have to square that number, perform the same calculus for all Chiefs running backs, and sum the totals. For Hunt, squaring his percentage gets you 82%, and the tiny amount for all other Kansas City rushers brings us up to 83%.
On the other hand, we have Philadelphia. LeGarrette Blount had 43% of all Eagles rushing yards (square of that is 18%), Jay Ajayi had 23% (5%), Corey Clement had 18% (3%), Wendell Smallwood had 10% (1%), and Darren Sproles and Kenjon Barner each had three percent (0%). That gave the Eagles a RB rushing concentration index of 28%. That was the second lowest rate in the league.
| Team | RB Rush Index | Win% |
|---|---|---|
| Chiefs | 83% | 0.625 |
| Rams | 69% | 0.688 |
| Steelers | 68% | 0.813 |
| Bears | 60% | 0.313 |
| Bills | 59% | 0.563 |
| Chargers | 58% | 0.563 |
| Browns | 58% | 0.000 |
| Colts | 55% | 0.250 |
| 49ers | 51% | 0.375 |
| Titans | 48% | 0.563 |
| Raiders | 48% | 0.375 |
| Broncos | 45% | 0.313 |
| Saints | 45% | 0.688 |
| Panthers | 44% | 0.688 |
| Falcons | 44% | 0.625 |
| Texans | 43% | 0.250 |
| Cowboys | 43% | 0.563 |
| Ravens | 43% | 0.563 |
| Bengals | 40% | 0.438 |
| Jets | 39% | 0.313 |
| Dolphins | 38% | 0.375 |
| Giants | 38% | 0.188 |
| Vikings | 37% | 0.813 |
| Jaguars | 36% | 0.625 |
| Lions | 36% | 0.563 |
| Packers | 35% | 0.438 |
| Patriots | 33% | 0.813 |
| Redskins | 33% | 0.438 |
| Buccaneers | 30% | 0.313 |
| Cardinals | 29% | 0.500 |
| Eagles | 28% | 0.813 |
| Seahawks | 20% | 0.563 |
The most interesting thing about that table? The correlation coefficient between RB Rushing Concentration Index and winning percentage was -0.01, which is about as meaningless a correlation you can find with 32 pairs of data points (your average random pair of 32 data points would have a much higher correlation!).
One year of data never tells us much, but it can tell us the absence of a trend. And if you think the trend is towards the best teams relying on one rusher, well, this is pretty clear evidence that such a hypothesis is wrong.