MLB DFS | Regression to the Mean Primer

MLB DFS | Regression to the Mean Primer

In an effort to define how this weekly column will evolve, using metrics and indicators, from such sites as Statcast (, to earmark a player either benefitting from good or bad luck on batted ball data will be the focus. Often, fantasy players will ride the hot hand or roster a player in MLB DFS just when he’s due for regression to the mean. This results in chasing the points one has already accrued rather being forward-thinking. Don’t fall into this trap.

To avoid this, targeting players either with a path to playing time as a result of injury or due to improved performance translates to profit. Or, targeting a slumping star who, as they say, will move toward the numbers on the back of the baseball card. For instance, Paul Goldschmidt started last year in a horrific slump. At the end of May, Goldschmidt owned a .209 average, .393 slugging percentage and many frustrated fantasy owners. However, Goldschmidt’s last 100 games yielded 25 home runs with a .334/.423/.608 slash line. 

With this in mind, four players who finished with expected batting averages (xBA) and expected slugging rates (xSLG) will be highlighted with the last week of drafts and baseball on tap this week. It’s not an exact science, but, using the data to identify players who could be primed to either bounce back or take the next step prove useful as drafts progress.

To prime the pump, here’s a chart with the leaders from three different indicators courtesy of Statcast with players of interest highlighted in yellow. For reference, FB/LD represents fly ball and line drive average exit velocity, hard hit percentage (HH) and expected slugging (xSLG):

Joey Gallo, Texas Rangers

  • .206 average in 2018, .228 xBA (22 point difference)
  • .498 slugging in 2018, .535 xSLG (37 point difference)

Not only did Gallo launch 40 home runs in only 500 at-bats last year, but he’s also a Statcast stud, appearing in all three lists above along with recording the third highest total of barrels (66) in the majors last year. His propensity to hit fly balls along with his prodigious power yields home runs. But, if he can carry over the gains from the second half last year during which he slashed .239/.340/.592 with 18 home runs in 184 at-bats (one every 10.2 at-bats) and an xSLG of .634, he could reach 50 in 2019. One cannot beat the shift, but Gallo can hit over it. If he hits for power to the opposite field, look out.

Nelson Cruz, Minnesota Twins

  • .256 average in 2018, .283 xBA (27 point difference)
  • .509 slugging in 2018, .558 xSLG (49 point difference)

Perhaps it’s the utility bias, but Nelson Cruz drifts to almost pick No. 100 in many seasonal drafts, falling five rounds below Khris Davis. However, Cruz seems destined to rebound in 2018, he’s produced a .278/.359/.537 slash over the last three years with 119 home runs in 1,673 at-bats. His BABIP crater last year deflated his average but key on Cruz ranking 11th overall in the majors in fly ball and line drive average exit velocity (97.2 MPH) and his one home run every 14 at-bats pace the last three years as a guide. There’s still some juice left in the tank, no pun intended.

Jackie Bradley Jr., Boston Red Sox

  • .234 average in 2018, .259 xBA (25 point difference)
  • .403 slugging in 2018, .455 xSLG (52 point difference)

Buying into all the swing changes and spring reports can be a risky venture. But, a teammate of J.D. Martinez could build on a breakout second half from last year. Bradley Jr. slashed .269/.359/.537 after the All-Star break with a .218 isolated power. Well below the radar, he accrued 17 home runs and 13 stolen bases last season and even though he will not hit in the top five of the Red Sox lineup, there are enough statistics to go around its deep lineup. Plus, his swing adjustment gets covered in detail here by Peter Abraham.

Gary Sanchez, New York Yankees

  • .186 average in 2018, .220 xBA (34 point difference)
  • .406 slugging in 2018, .461 xSLG (55 point difference)

Those searching to differentiate can locate power in Gary Sanchez at catcher. His value in DFS will be depressed due to last year’s injuries and bad luck. Sanchez still resides in the top-two catchers taken in seasonal drafts but could be a bargain due to the positive regression to the mean in the season ahead. Sanchez remains one year removed from 33 home runs, 90 RBI and a .278 average in 122 games.


Other names to file away for potential regression:

  • Ryon Healy: 25 point differential in batting average and 26 points slugging.
  • Chad Pinder: 13 point differential in batting average and 76 points difference in his xSLG (wow).
  • Lewis Brinson: 28 point differential in batting average and 53 points difference in xSLG.

Once data starts to accrue, players of note will emerge each week as targets to maximize lineup construction on FanDuel and DraftKings. Be sure to stay with the staff at The Quant Edge to get ahead of the competition.

Statistical Credits: