Dash's Play-by-Play: Oh, How Wrong Our Fantasy Football Predictions Were!

By Dash Davidson 2015/11/25

Note: Dash's Play-by-Play is an occasional series that explores data in the world of sports.

The NFL regular season is just past its midpoint, which means the fantasy football season is quickly approaching the playoffs. With much of the season behind us, I thought it would be interesting to take a pause from the weekly rigor of waiver wire pickups, matchup analyses, and sit-start decisions to look back at which players have been underperforming and overperforming this year.

To build this analysis, I’ve scraped the final Yahoo preseason rankings for standard fantasy football scoring leagues as well as the most recent ones reflecting all games played through week 10.

To be fair, it has been a weird NFL season thus far, with surprising performances and rashes of untimely injuries. But the main takeaway from the data is that this year’s preseason rankings and projections were particularly bad. Here is a scatter plot of all the running backs currently ranked in the top 200 on Yahoo Sports, with their actual current ranking on the y-axis and their preseason ranking on the x-axis.

Several outliers quickly jump off the chart: That mark all by itself in the bottom middle? That’s Devonta Freeman, the #1 player in all of fantasy football. In the preseason, he was forgotten across the board as the #101 ranked player. On the opposite end of the spectrum, outliers way up the y-axis are Eddie Lacy and C.J. Anderson. They were consensus first-round picks at #4 and #7 in the preseason, but they’ve not been able to crack the top 150 in the actual rankings.

These are fantasy season-killing types of miss-projections. For all the emphasis put on the importance of drafting running-back studs at the very beginning of fantasy drafts, there were many significant busts. The circles colored blue represent players ranked in the preseason top 30. About the only early running-back pick that has performed as expected is #1 overall pick Adrian Peterson, who checks in at #12 in the midseason update.

If we drop a trend line on the running back scatter plot, we see that there is a positive correlation between preseason ranking and actual ranking—albeit a very weak one. If we expand our scatter plot to include the other high-impact fantasy positions—QBs, WRs, TEs—we can see that different positions have different correlations between preseason and actual rankings.

The preseason rankings for tight ends were fairly accurate. Given the low turnover rate for this position and the general lack of competition on most teams for targets, this makes sense.

What makes less sense is the negative relationship between preseason and actual rankings for quarterbacks. Many quarterbacks have performed well this season, reflecting the trend throughout the league of relying more and more on passing for offense, and the scatter plot reflects this with many dots clustered low on the y-axis.

A closer look at the quarterbacks who have outperformed their preseason rankings shows that it is a cohort of veterans: Eli Manning, Philip Rivers, Tom Brady, Carson Palmer, Drew Brees. This indicates that preseason rankings may have been overly cautious on these aging producers and overly optimistic on younger quarterbacks such as Andrew Luck and Russell Wilson. Of course, one very veteran quarterback is the worst outlier on the scatter plot. That's Peyton Manning, so there certainly are exceptions to any trend.

Wide receivers were generally well-projected, too, with most of the marquee early-round picks working out for owners. The cluster of dots right around the intersection of the x- and y-axis indicates that top preseason ranks have lived up their billing.

How can we look at this data to more quickly identify which players have outperformed or underperformed their preaseason rankings? Take a look at the following chart, which lists the top 200 players in the current Yahoo rankings, broken down by position. The length of the bar for each player along the x-axis shows how well they have performed versus the player’s preseason projection (I used the simple calculation of Preseason Ranking minus Actual Ranking). The width of the bar indicates how many fantasy points that player has tallied, weighing the relative importance of each player’s performance.

How have the players on your team performed? Who did you have the opportunity to draft that you now wish you had? Hopefully, for your sake, you have fewer regrets looking at this visualization than I do.


Submitted by Javier B. on

Well done! Hope you make another study in order to prepare next season Draft!

Submitted by Dash Davidson (not verified) on

Thanks Javier!