By the Numbers: Impact of Stacking in DFS
Dozens of fantasy “experts” (I hate that term), myself included, pump out in-season content touting their top NFL DFS stacks and correlation plays each week. You see the same generic articles throughout the industry at times almost blindly choosing QB-WR combinations paired with a good matchup.
This can absolutely be a viable strategy; but the ultimate goal for many people in DFS is to take down a large GPP. I found myself questioning the value of specific stacks and correlation plays against others. What types of stacks are showing up the most at the top of these leader boards?
In this study, I have compiled data from lineups that finished in the top-10 of the Millionaire Maker and Sunday Million from Weeks 1-17. These are DraftKings’ and FanDuel’s largest GPPs.
Examining both platforms each week left me with a total sample size of 160 lineups from the Millionaire Maker (no MM in Week 16) and 170 lineups from the Sunday Million.
I opted to chart these two platforms independently of each other because of both scoring differences (e.g., PPR and 100-yard bonus on DraftKings) and roster capability differences (e.g., Kickers and no FLEX position on FanDuel).
The stacks that were charted are relatively self-explanatory. For example, lineups with a Quarterback and Wide Receiver from the same team were charted as a “QB-WR” stack and so forth. A “Naked QB” is where a QB was not stacked with one of his teammates. A “Game Stack” is where four or more skill position players from the same game, regardless of the team, are present in the same lineup. A “No Stack” is where zero stacks are found while examining the lineup.
For the purpose of this study, a correlation play is noted when an opposing RB, WR, or TE is also included with a stack from the same game. For example, in Week 8 the Saints faced the Giants. A lineup where Drew Brees is stacked with Brandin Cooks but also included the correlation play of Odell Beckham Jr. was charted as a “QB-WR” stack but also a “QB-WR + cor” stack.
The goal of this study is to provide data highlighting what types of stacks provided the most upside during lineup construction for large GPPs and to see if those findings were differentiated by DFS platform in the 2015 NFL season.
DraftKings Top 10 Stacks
There were three major differences I found when examining top-10 lineups on DraftKings in comparison to FanDuel.
The first is that TE-WR stacks were found 6.99% more often on DK than on FD. That may not sound like a huge number but out of the entire sample size just one type of stack occurred in more than 23.75% of top-10 lineups (QB-WR at 43.75%). Finding a 6.99% disparity between platforms in that main 23.75% is substantial.
RB-DEF stacks on DK occurred 6.44% more often than RB-DEF on FD. It is quite possible this can be attributed to pricing differences on each site. It is generally easier to fit in a DEF or TE of your choice on DK, as the prices at those positions are much softer. For example on DK you have $5,555.55 to spend per position (50K cap, 9 roster spots). A DEF on average will cost you roughly $3,000 or about 6% of your cap. In contrast, on FD you will spend roughly 7.5% of your cap on DEF (60K cap, 9 roster spots, $4500 avg. price).
The third-highest disparity between the two platforms was QB-TE. These stacks were found on 6.29% more top-10 DK lineups than on FD. Again, as stated above, the soft pricing on DK allows more flexibility during lineup construction because of pricing and the available FLEX position. Yes, of course you can spend all the way up on DK for Rob Gronkowski at over $8,000 but if you choose to punt or take advantage of value in a given week with a minimally priced TE the difference is much greater than on FD. For example in Week 13 Scott Chandler got a huge bump in value with Gronkowski out against the Eagles. Chandler was minimum priced on DK at $2500 (5% of salary cap) but on FD he was still $5300 (8.83% of salary cap).
FanDuel Top 10 Stacks
It is rare to see a specific stack occur more often on FanDuel than on DraftKings because of pricing and the FLEX position but two situations still managed to stand out in this study.
TE-RB stacks appeared in top-10 lineups 3.46% more often on FD than on DK. I attribute this to scoring differences on the platforms more than anything else. Without the 100-yard bonus and full PPR that DK enables, the touchdown stat is much more important on FD. RBs who get goal line carries or TEs that get red zone targets are much more valuable on this platform because there are fewer ways to hit tournament value without multiple touchdowns.
Naked QB showed up 3.09% more often in top-10 Sunday Million lineups than in Millionaire Maker lineups. Going “naked” at QB proved to be a very effective way to get exposure to multiple top plays of the week. For example, in Week 17 Odell Beckham Jr., Antonio Brown and Julio Jones all had extremely favorable matchups. It was nearly impossible to fit in all three to your lineups but having exposure to all three seemed to be a necessity. The best way to do this was to go naked at QB with Eli Manning (the cheapest QB option of the three but offered similar upside) and to roster Brown and Jones. By using this strategy you protected yourself if Beckham went off, yet you still were able to fit in the other top WR plays of the week.
Takeaways
By far the most popular stack included in top-10 lineups from the Millionaire Maker and Sunday Million GPPs was QB-WR at 43.75% and 40.59% respectively. This stack showed up in roughly twice as many lineups as the next closest category. QB-WR + cor also proved to be the best performing correlation play at 7.50% and 7.06%.
RB-WR came in as the next most frequent stack at 23.75% and 20.59% on DraftKings and FanDuel, respectively. I personally was a bit surprised to see RB-WR so high on the list on both platforms due to its slightly negative correlation (-0.07). However, when you really think about it, there is no reason to avoid these players from the same team if they are strong values individually. For example, Antonio Brown paired with DeAngelo Williams or Julio Jones paired with Devonta Freeman proved to be a fantastic GPP stack last season. They did in theory cap each other’s TD upside but what is actually more important is when both players were productive they helped move the chains. More drives being kept alive meant more TD opportunities for the entire offense. Each additional yard gained by either player puts them closer to the end zone.
The poorest performing correlation play of this study was RB-DEF + cor at less than 1% on both platforms. This makes perfect sense. The entire premise of the RB-DEF stack is the idea that when a team (or defense) is ahead the RB you stack with that DEF will get more volume to help kill the clock and control the ball. Also the more risks an opposing offense has to take to get back into a game the higher the chance of turnovers for your defense. The better that aforementioned RB or DEF does their job, the less opportunities the correlation play paired with this stack will have to score fantasy points.
The best performing triple stack was QB-WR-TE but I found that it is much more to your advantage to go with a full “Game Stack” in large GPPs. Game Stacks were found in 14.38% and 15.29% of top-10 lineups. Game Stacks appeared in roughly 5% more top-10 lineups than every triple stack charted combined. This was consistent on both DraftKings and FanDuel.
