Statcast Pitcher Studs and Duds - Advanced Metrics Leaders for xERA (Week 8)

May 15, 2023

Connelly Doan examines fantasy baseball pitcher risers and fallers, and whose xERA could make them adds, drops, or trade targets for Week 8.

Welcome back to another edition of RotoBaller’s Statcast Pitcher Studs and Duds article series! Each week, I will select one advanced metric, choose two pitchers with strong values and two with poor values, and analyze what those values may mean for future performance. There are many ERA skill indicator metrics that fantasy managers can use to understand how pitchers are performing beyond their peripherals. I wrote about SIERA last week, and this week I will write about expected ERA (xERA).

xERA is a 1:1 translation of the Expected Weighted On-Base Average (xwOBA) converted to the ERA scale. Like SIERA, xwOBA takes into account the amount of contact and the quality of that contact a pitcher allows in an attempt to credit them for the moment of contact. Unlike SIERA, xwOBA/xERA does not factor in ballpark conditions.

SIERA and xERA may be similar, but both are useful for fantasy managers. We are starting to gather a useful amount of data so fantasy managers can start identifying over and underachievers and buy-low/sell-high candidates. With that, let's dive into some xERA Studs and Duds!

xERA Studs for Fantasy Baseball

All stats are current as of Sunday morning, May 14, 2023.

Joe Ryan, Minnesota Twins

6-1, 2.16 ERA, 0.84 WHIP, 2.15 xERA

Joe Ryan is a name fantasy managers have been familiar with for some time. His first full season in 2022 was promising, and he has taken more positive steps this season, putting together a 6-1 record with a 2.16 ERA, 0.84 WHIP, and 29.7% strikeout rate. His stellar 2.39 xERA supports his strong start. What changes has he made to lead to his improvements?

Ryan made substantial changes to his pitch arsenal that have been very effective. He has always relied heavily on a four-seam fastball but added a split-finger fastball and a sweeper this season. The splitter has been his main secondary pitch at 27.4%  usage and has yielded a .194 batting average against with a 13.4% swinging strike rate.

Joe Ryan, 93mph Fastball and 84mph Splitter, Overlay.
Tunneling... pic.twitter.com/Th1A1VCoG7

— Rob Friedman (@PitchingNinja) May 13, 2023

Ryan's new pitches have allowed his overall swinging strike rate to jump from 11.4% to 14.3% and his strikeout rate to jump from 25% to 29.7%. His pitch movement and location have led to a chase rate in the 99th percentile of baseball, which has helped the strikeouts but also helped cut his walk rate in half.

Ryan has pitched very well this season and his underlying stats support it. His new pitches have helped take his game to another level. There is no reason to think he won't continue to pitch well if he can locate his fastball in the top of the zone and get swings-and-misses and chases on his secondary pitches.

Spencer Strider, Atlanta Braves

4-1, 2.51 ERA, 0.92 WHIP, 2.39 xERA

Spencer Strider burst onto the fantasy scene last season and has picked up right where he left off this season. The 24-year-old has gone 4-1 with a 2.51 ERA, 0.92 WHIP, and an insane 42.9% strikeout rate through his first eight starts. He has also compiled an excellent 2.39 xERA to back things up. How has he been so successful while essentially relying on two pitches?

The bottom line is you can be a successful starter with two pitches when both are completely overpowering. Strider's fastball comes in at 97 mph, putting it in the 93rd percentile of baseball. The pitch's spin rate is in the 83rd percentile of baseball, giving it a perception of rising. His slider also has above-average movement and a ridiculous 27.7% swinging strike rate.

The average MLB fastball drops 15" from hand to plate.
This Spencer Strider heater dropped only 5".
That's totally insane. pic.twitter.com/lvx0remHNl

— Codify (@CodifyBaseball) May 12, 2023

Strider has actually allowed harder-than-average contact with an 18.8-degree launch angle, but he allows such little contact that it hasn't mattered. The rest of his Statcast profile is red across the board and his expected metrics are all excellent. He should continue to be a top-end fantasy starter with one of baseball's best pairing of pitches.

xERA Duds for Fantasy Baseball

All stats are current as of Sunday morning, May 14, 2023.

Michael Kopech, Chicago White Sox

1-4, 5.74 ERA, 1.56 WHIP, 7.61 xERA

Michael Kopech turned in an encouraging 2022 season but has not been able to replicate it whatsoever in 2023. He has managed a 5.74 ERA, 1.56 WHIP, 21.4% strikeout rate, and 14.6% walk rate through eight starts. Even more troubling, his 7.61 xERA is significantly higher than his ERA. Should fantasy managers hold out any hope he can return to 2022 form?

As of now, there are not any signs to suggest so. Walks have been the primary issue. Kopech's walk rate in 2022 was high at 11.5%, but 14.6% this season has been too high to work around.

Additionally, he has gotten crushed when contact has been made. Kopech's exit velocity and hard-hit rate are in the 12th and sixth percent of baseball, respectively, to go with a 19.6-degree launch angle. His BABIP is surprisingly low at .246, but he has allowed a lot of contact out of the park with a 2.55 HR/9 rate and a 20.7% HR/FB rate.

Fantasy managers were likely excited for Kopech this season, but few things have gone right for him. He has put too many batters on for free and has allowed a lot of hard contact in the air. His xERA suggests that he should actually be doing even worse. At this point, he has too many facets of his game to fix to make him a fantasy hopeful.

Rich Hill, Pittsburgh Pirates

3-3, 4.35 ERA, 1.48 WHIP, 6.55 xERA

Rich Hill has once again been a useful fantasy option at times this season. The veteran has compiled a 3-3 record with a 4.35 ERA, 1.48 WHIP, and 19.9% strikeout rate in eight starts. However, his 6.55 xERA tells a different story. Does the 43-year-old still have something to offer fantasy managers, or should they be wary?

Hill is no longer a strikeout option due to his decreased velocity, so fantasy managers should take that out of the equation from the beginning. Looking deeper, his batted-ball profile has been above-average, allowing slightly less hard contact than league-average with a 17.1-degree launch angle. However, the rest of his Statcast profile is poor, particularly his expected stats.

Hill's xERA falls in line with the rest of his expected statistics, but his batted-ball profile seems to contradict it. Hill will likely allow more hits than average given his crafty approach and lack of overpowering stuff, but he seems to make things work overall. I would not suggest Hill in a roto league given his high WHIP and low strikeout rate, but I do think he is worth starting in decent matchups in points leagues at this time.

More Sabermetrics and Statcast Analysis