Filling the Flex: RB or WR?
The Flex Spot. Diverse. Troublesome. Essential. If you’re like me, then odds are, you’ve found yourself faced with the frustrating question of: “Who am I using to fill my flex?” We’re in a time now where the position requirements in themselves have evolved from the simple times of running back/wide receiver slots, to the new kid on the block option of the Superflex. Regardless of the format you may play in, deciding between the player, and thereunto the position that you are going to place in your flex can be quite the weekly dilemma. The debate of the high floor running back play vs. the high upside wide receiver play has haunted many for years. This is the issue that I have set out to help all of you get answers to, once and for all. For analytic purposes, all research and stats pertaining to this article will be in what I consider to be the most neutral of all formats in terms of scoring, 0.5PPR, Non-Superflex.
When considering the options for filling your flex, depending on your roster constructions, typically your choice will lie with a player whose positional rankings falls in the range of 16-40. Although the names change year in and year out, these are the players that most fantasy managers find themselves debating between on a weekly basis. If you’re like me, you most likely fall on a specific side of the wide receiver vs. running back debate. I, for years, have found myself leaning running back week after week in the flex. Before researching, I always preferred the floor play in my flex spots. To me, it was more important to guarantee a set amount of points from a flex, than it is to swing for the fences. Due to that, I have always leaned towards running backs, with the concepts of volume, and opportunity for both carries and receptions on a given week, driving my beliefs. Regardless of the results, each time I have stuck to my guns, without ever really questioning if I was correct. That is, until I decided to put this to the test.
Compiling data from the last three seasons, I dove into the numbers, hoping to find an answer to my problem. The season end points per game (PPG), the highest weekly output (TOP), the lowest weekly output (BOT), and the percentage of games the player had under 9 fantasy points (BUST), were all compared for the RB16-RB40 and WR16-WR40. This may sound like a lot, but don’t worry girls and boys, I’m not going to be the guy who drowns you in stats. Numbers are great, but let’s break this down from a fundamental standpoint.
When looking across the three season span of 2017, 2018, and 2019, the PPG were nearly identical between the two positions. Wide receivers across that span averaged a PPG of 10.5pts with a standard deviation of 1.05. Running backs across that same span averaged a PPG of 10.0pts, with a standard deviation of 1.37. For those of you not accustomed to working with standard deviation, it is a representation of how far an overall average is from each value in a population. With each of the standard deviations being as low as they are, is shows that there is not a wide variance between the WR’s and RB’s of this group. Meaning, that there are no true outliers at either position that would skew the PPG stat towards a higher or lower number.
The biggest takeaway from this, is that a player in either positional group will generally finish the season with a similar end of season PPG, as a player from the other positional group. This is helpful when considering the weekly playability, as well as the overall process that you take to construct your rosters. Those players you consider on draft day to be your “potential flex plays” on a regular basis make up a large portion of your roster. Understanding that the average weekly point total that these players produce for you is nearly identical, regardless of their position, is huge. It can tell you that on draft day, if you are looking from a PPG mindset, it is more important to focus on rounding out your roster with players you like, than forcing a pick solely due to it being a WR or RB.
When looking at the TOP and BOT for each player in the group, this is where the analysis finds its most revealing of results. For the WR’s the average TOP for the 3 seasons was 25.0pts, and the average BOT was 1.8pts. For the RB’s the average TOP was 23.6pts, and the average BOT was once again 1.8pts. The standard deviations for the WR’s numbers were 6.25 and 1.28 respectively, while those for the RB’s were 4.33 and 1.49 respectively. Diving into these numbers shows us much more variance than the PPG comparison. These numbers show that WR’s although having a larger value of TOP score for a week, are much less consistent with producing said TOP scores. The RB’s have a slightly lower average TOP score on any given week; however, are more closely pooled together, and thus are most likely to produce a higher valued TOP score for a week.
In simpler terms, although the WR position as a whole for your flex spot may give you a higher score on a weekly basis, there are fewer players from the WR position that will in turn give you said higher values. The RB position on the other hand, having a lower average TOP high score, does have more individuals scoring higher TOP scores when compared to the WR’s. This when paired with the identical BOT scores of 1.8 for each position shows us that although WR’s may produce a higher score, you have a better chance of hitting on a high scoring RB than a high scoring WR on a given week. This gives the “ceiling play” edge surprisingly to the RB position.
The last data to delve into was that of the BUST category. The average BUST across the span for WR’s was 48% and for the RB’s it was 49%. These two were paired with standard deviations of 11% and 12% respectively. This level of variance, along with the nearly identical 50/50 bust and non bust rate, led to the discovery of quite a few outliers. In the pool of players, I singled out those who fell outside of the 35% to 65% threshold, to see which of the players could be considered extremely consistent, or extremely inconsistent with their weekly scoring.
When looking at the names for respective categories, a clear pattern emerged. For those falling into the extreme consistency outlier group, we found WR’s with large team target shares, and those who experienced multi game injuries. The same could be said about the RB position for those in the same category were backs in lead roles, and those who experienced multi game injuries. To give a few faces to the players, these in question are the Steffon Diggs’ and Julian Edelman’s at WR and Marshawn Lynch’s and Marlon Mack’s at RB. Those falling in the inconsistent category at WR were those big bodied WR’s who relied heavily on TD production, and big play ability. From the RB position we find that those most inconsistent in production were surprisingly those scat/satellite backs who most considered to be safe floor plays due to their dual threat nature. These players were the Mike WIlliams’ and TY Hilton’s at WR and the Tarik Cohen’s and Duke Johnsons’s at RB.
The WR inconsistencies found in the research were very predictable. Typically the big bodied red zone threats will always be inconsistent without a massive volume to sustain them. What was shocking was the revelation on the RB front. We’ve been preached to year after year that the RB’s with true receiving upside are the ones we should all be targeting. What this study shows is that, although prevalent for the stud RB’s higher in the rankings who carry the lead back roles, when it comes to backups and satellite backs, chasing receiving upside may not be your best bet. They are inconsistent and unless an OC goes out of their way to make them relevant in the offense, the typical receiving back can tank your team on a weekly basis from the flex position.
We’ve come a long way through this article, and a lot has been laid out before you. Everyone has their own strategy when it comes to fantasy, but in the end, understanding trends and patterns can put you, as a player, ahead of the crowd. Knowing when to play certain players, at certain positions, can give you the edge that your opponent doesn’t have. I can’t make your decisions for you, and ultimately it comes down to gut feelings for most, but if you learn anything from this article, it should be that consistency is key. With so many statistical similarities between the WR’s and RB’s, it ultimately comes down to who you can rely on weekly. Knowing when to, and when not to chase targets, TD’s, and volume is huge. Although we have learned that choosing between A WR and RB makes little difference at the flex position, we too learned that choosing WHICH WR and RB to take is what truly matters. Filling the flex is vital to a trophy run, and now hopefully you’ve got the info to help you take home that ship.