The Consistency Reports: Running Backs
The question of valuing players is the seemingly never-ending issue when it comes to fantasy football. Should you target a player with upside, or should it be someone who might have a lower ceiling but provides you with consistency week to week? What about if you had a way to combine both elements in one ranking? Well, here at FFStatistics we have attempted to do just that with our Consistency Rating (COR). COR is created by taking a player’s calculated ceiling and dividing it by their coefficient of variation (more information on these and the math behind them at the bottom of the article). If you do not fancy doing the math yourself, then our consistency tool provides you with all the data. As an added bonus you will also find out how often players scored within certain brackets, top-five, top-12, 13-24, 25-36 and beyond.
Using COR, we can get an easy snapshot of where players rank on a weekly basis. We can also compare their COR value to their average fantasy points total. By looking at the difference between the two values, we can identify various subsets of players. Some players posted an average that looked great but using COR we can find out whether they were reliable or not on a week-to-week basis. The same goes for players who posted average points totals which were not great. Some did it and were wildly inconsistent, others were actually pretty reliable.
This article will take a look at the consistency of the running back position as a whole. Then we will dive into a couple of players whose ranking by COR differed from their ranking based on their weekly average points total.
2018 Consistency Ratings
|Player||Team||G||Average||Std Dev.||Weekly Floor||Weekly Ceiling||CV||COR||COR Rank||OVR Rank||COR vs. OVR|
There will be no surprises to see the likes of Todd Gurley, Saquon Barkley and Melvin Gordon top this list. In fact, the only top-10 name who would cause a slight double take before the season is James White. Outside of top-10, there are some interesting names. There are also some names that came from nowhere to provide value to fantasy owners. Running back is one of the more volatile positions, but there will not be many shocks when you look down the COR rankings. However, when you look at the difference between players overall ranking, based on weekly average and their COR rankings, we start to see some differences. Let’s take a look at some of those players who saw a difference in their rankings.
High Variance Running Backs
Below is a list of backs who provided fantasy owners with a lot of joy last season. However, comparing weekly average to COR there are some interesting changes.
Percentage of weekly finishes in the top-five, top-12, 13-24 and 25-36 for Marlon Mack, Leonard Fournette and Tarik Cohen in 2018.
Marlon Mack, IND
The early part of Mack’s season was hampered by injury. When he was on the field he had the ability to produce the spectacular. In four of the 12 weeks he was on the field Mack graded out as a top-five running back. However, in three of those weeks, he was actually outside of the top-36 at the position. He was outside of the top-24 in a further four. The positive here is that Mack ended the season healthy and after the Colts decided to go away from the running back position in the draft. He should find himself the number one again.
The problem is that Mack has somewhat of an injury history, and he is not known as a tough between the tackles runner. In tight games that could limit his opportunities and mean that as fantasy owners there will be plenty more frustrating weeks.
Leonard Fournette, JAX
Fournette is another back who saw his 2019 season hampered by injuries. Frustratingly, in the end, he only suited up for eight games. When Fournette was on actually on the field last season his performances varied. He was a top-24 running back in 50% of those games, but also outside of the top-36 25% of the time.
The lack of any passing game was a really big detractor from Fournette’s ability to produce for fantasy owners. With Nick Foles under center and some improvements on their offensive line, there is potential for a solid year from Fournette, if he can stay healthy that is.
Tarik Cohen, CHI
Much like the other two on this list, Cohen is extremely talented. However, Cohen has been stuck in a timeshare with Jordan Howard most of his career. Last season, that led to a lot of frustration for Cohen owners. 25% of the time he was a top-12 option. In three of those four weeks, he was actually top-five. However, on another 25% of occasions, Cohen finished outside the top-36 at the position. Things looked to be improving as the Bears shipped Howard to the Eagles. However, the Bears drafted David Montgomery. Montgomery could potentially split time with Cohen this season along with Mike Davis.
Cohen is a wonderfully talented back but he is not an every down playmaker, limiting his fantasy value. In best ball leagues he is right up there but in standard fantasy leagues, all owners need to temper expectations entering draft season.
Low Scoring But Consistent Running Backs
The following list of backs may seem confusing because the COR number associated with them is actually lower than the guys above. That is because COR takes into account the ceiling of the players as well as their consistency. However, what the names below will hopefully demonstrate is that less desired backs provided similar levels of consistency to their more highly sought after counterparts.
Alex Collins & Kenneth Dixon, BAL
This is a fascinating pairing. Both finished extremely high when you look at the difference between their COR ranking and their average weekly points total. Collins owners will have been frustrated seemingly every week as he struggled to gain traction and seemed to have fantasy points vultured left, right, and center. However, Collins ranked as the 12th most consistent running back. Collins finished as a top-24 running back in five of the 10 weeks he played. In those remaining five he was still a top-36 back in another four. It possibly was not what you were hoping for when you drafted him, but Collins returned starter value more often than not.
Dixon only has a six-week sample size. He was a top-24 starter on two occasions and top-36 on a third. That makes a grand total of eight weeks combined in which this pair of Ravens were top-24 running backs. Throw in another four from Gus Edwards and that makes 12 out of 16. Where this comes into relevance is with the addition of Mark Ingram. Yes, Edwards and Dixon are still there. Yes, they will likely steal touches. However, Ingram has the potential to be an extremely consistent option for you this season. Additionally, Ingram also has a talent upside that the Collins, Dixon and Edwards trio cannot match. Ingram could be a gem of an option in 2019. Especially with defenses having to account for a certain running quarterback in Lamar Jackson.
Jalen Richard, OAK
The entire Oakland offense struggled to do anything with regularity in 2018. However, Richard ranked just outside the top-32 running backs in terms of consistency and was a top-24 running back in 6-of-16 weeks. In a further five weeks, he fell in the 25-36 bracket. This means that in deeper leagues or as a flex he was useful in 11 out of the 16 weeks last season. What is impressive is that Richard managed to be sneakily useful for fantasy purposes despite an extremely marginalized role in the Oakland offense. In fact, Richard had more receptions last season than he did carries.
What Richard’s numbers demonstrate is the potential value of Josh Jacobs. If Richard managed to be a semi-useful fantasy option in 11-of-16 weeks, Jacobs can be a valuable commodity as a running back this season, especially if he is a part of the passing attack.
The Math Behind the Stats
For those of you interested here is how all of the numbers that make up the consistency rating (COR) are produced. I am going to go full geek mode here so I fully understand if you just want to bypass this section and take my word for it!
Standard Deviation and Coefficient of Variation
First, we need to look at the average and standard deviation for that player. The standard deviation quantifies how spread out the numbers are. However, raw standard deviation numbers are messy to look at and hard to take in. They are also biased by the average of the player. A player with a lower average will have a bigger change in standard deviation for smaller relative changes in fantasy points than a player with a larger average weekly score. Therefore, we use another factor called the coefficient of variation (C.V.). C.V. takes the standard deviation and divides it by the average, allowing you to compare two players side by side regardless of their weekly average.
There is a downside of using C.V. If a player is consistently bad he will have a low C.V. and rank highly if we simply ranked players by that metric. Therefore, we need to look at a way to incorporate a players weekly points total. To do this we can calculate a players floor and ceiling, using their average and standard deviation. Over time the fantasy points scored by a player follow a normal distribution. With normal distribution we see the percentage of observations fall within one, two, or three standard deviations either side of the mean.
68% of the observations will fall within one standard deviation either side of the mean. 95% within two standard deviations and 99.7% within three standard deviations. The wider we go with the standard deviations the harder it is to accurately predict a player. Therefore, the floors and ceilings are calculated by looking at the values which fall one standard deviation either side of a players weekly average.
Finally, the COR itself. COR is calculated by taking a player’s calculated ceiling and dividing it by the C.V. The higher the number the better that player ranks as a risk/reward play for fantasy owners. COR gives weight to players who have a high ceiling, but also to those who are consistent. Players who consistently put up big points totals rank highly and players who are highly variable fall further down the rankings.