Last year, I looked at the unusual running back by committee in Arizona in 2013. Rashard Mendenhall was the team’s primary back, but he averaged 3.17 YPC that season, while Andre Ellington averaged 5.53 YPC. To measure how “unusual” the split was, I came up with the following methodology: calculate the difference between the YPC of the top two running backs (as measured by carries) on each team, and multiply that difference by the number of carries given to the running back with fewer carries. So for the 2013 Cardinals, the difference between Ellington and Mendenhall in terms of YPC was -2.36; we multiply that by 118 to get a value of -278. For 2014, the most extreme result along this line came in Minnesota.
Matt Asiata had 164 carries for the Vikings but gained just 570 yards, for a 3.48 YPC average. Meanwhile, Jerick McKinnon rushed only 113 times but picked up 538 yards, a 4.76 YPC average. So McKinnon averaged 1.28 more yards per carry than Asiata. Then, we multiply -1.28 by 113, which produces a value of -145, the most extreme of the 32 teams last year.
The reason for this two-step process is that when dealing with backup running backs, you sometimes get small sample sizes. For example, Latavius Murray averaged 5.17 YPC on his 82 carries, but the Raiders split doesn’t count quite as extreme as the Vikings split based on this method. Also, the Cowboys split would look pretty funky if you didn’t penalize RB2s that had only a handful of carries:
|Rk||Tm||Running Back||Car||Yards||YPC||Running Back||Car||Yards||YPC||Value|
|1||MIN||Matt Asiata||164||570||3.48||Jerick McKinnon||113||538||4.76||-145|
|2||OAK||Darren McFadden||155||534||3.45||Latavius Murray||82||424||5.17||-141|
|3||IND||Trent Richardson||159||519||3.26||Ahmad Bradshaw||90||425||4.72||-131|
|4||DAL||DeMarco Murray||392||1845||4.71||Joseph Randle||51||343||6.73||-103|
|5||PHI||LeSean McCoy||312||1319||4.23||Darren Sproles||57||329||5.77||-88|
|6||NYG||Andre Williams||217||721||3.32||Rashad Jennings||167||639||3.83||-84|
|7||TAM||Doug Martin||134||494||3.69||Bobby Rainey||94||406||4.32||-59|
|8||WAS||Alfred Morris||265||1074||4.05||Roy Helu||40||216||5.4||-54|
|9||BUF||Fred Jackson||141||525||3.72||Anthony Dixon||105||432||4.11||-41|
|10||TEN||Bishop Sankey||152||569||3.74||Shonn Greene||94||392||4.17||-40|
|11||NOR||Mark Ingram||226||964||4.27||Khiry Robinson||76||362||4.76||-38|
|12||CLE||Terrance West||171||673||3.94||Isaiah Crowell||148||607||4.1||-25|
|13||NYJ||Chris Ivory||198||821||4.15||Chris Johnson||155||663||4.28||-20|
|14||CHI||Matt Forte||266||1038||3.9||Ka'Deem Carey||36||158||4.39||-18|
|15||ATL||Steven Jackson||190||707||3.72||Devonta Freeman||65||248||3.82||-6|
|16||DET||Joique Bell||223||860||3.86||Reggie Bush||76||297||3.91||-4|
|17||ARI||Andre Ellington||201||660||3.28||Stepfan Taylor||63||208||3.3||-1|
|18||SFO||Frank Gore||255||1106||4.34||Carlos Hyde||83||333||4.01||27|
|19||STL||Tre Mason||179||765||4.27||Zac Stacy||76||293||3.86||32|
|20||SEA||Marshawn Lynch||280||1306||4.66||Robert Turbin||74||310||4.19||35|
|21||PIT||Le'Veon Bell||290||1361||4.69||LeGarrette Blount||65||266||4.09||39|
|22||NWE||Shane Vereen||96||391||4.07||Stevan Ridley||94||340||3.62||43|
|23||MIA||Lamar Miller||216||1099||5.09||Daniel Thomas||44||168||3.82||56|
|24||GNB||Eddie Lacy||246||1139||4.63||James Starks||85||333||3.92||61|
|25||CAR||Jonathan Stewart||175||809||4.62||DeAngelo Williams||62||219||3.53||68|
|26||DEN||C.J. Anderson||179||849||4.74||Ronnie Hillman||106||434||4.09||69|
|27||SDG||Branden Oliver||160||582||3.64||Donald Brown||85||223||2.62||86|
|28||JAX||Denard Robinson||135||582||4.31||Toby Gerhart||101||326||3.23||109|
|29||BAL||Justin Forsett||235||1266||5.39||Bernard Pierce||93||366||3.94||135|
|30||CIN||Jeremy Hill||222||1124||5.06||Giovani Bernard||168||680||4.05||171|
|31||KAN||Jamaal Charles||206||1033||5.01||Knile Davis||134||463||3.46||209|
|32||HOU||Arian Foster||260||1246||4.79||Alfred Blue||169||528||3.12||282|
A few comments:
- Darren McFadden averaged 1.17 fewer YPC than Rashad Jennings in 2013, and 1.73 fewer YPC than Murray in 2014. Make of that what you will, but it will be very interesting to see how McFadden fares in Dallas given that history.
- We know Alfred Blue was not very effective last year, but this really puts it in perspective. Foster averaged 1.67 YPC more than Blue, the largest differential of any RB1-RB2 combo last season. Blue also had the most carries of any RB21 last year, which is why Houston produced such a large value of “unusualness” under this formula.
- Not shown: for five teams, their quarterback was actually second on the team in carries. Those five were San Francisco, Seattle, Miami, Carolina, and… Chicago. Ka’Deem Carey had just 36 carries, which is probably a better sign of how much the Bears relied on Matt Forte than Forte’s 265 carries.
- You won’t be surprised to learn that Trent Richardson had the lowest YPC of any RB1 last year, narrowly edging out Ellington and Andre Williams. Among RB2s, Donald Brown‘s pathetic 2.62 YPC average truly stands out. That’s the third lowest YPC average by any running back (minimum 75 carries) since 2000.
- Defined as the running back who was second among running backs in carries. [↩]