Statcast Pitcher Studs and Duds - Advanced Metrics Leaders for xwOBA (Week 12)

June 12, 2023

Connelly Doan examines fantasy baseball pitcher risers and fallers, and whose xwOBA could make them adds, drops, or trade targets for Week 12.

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. With nearly two months in the books, fantasy managers can start building more accurate profiles for pitchers who could continue to help or hurt their teams. This week, I'll take a look at the expected weighted on-base average on contact (xwOBA).

wOBA is used to establish the value a player brings per plate appearance using unintentional walks, base hits, and hit-by-pitches; it is scaled like on-base percentage. Expected wOBA takes wOBA but applies weights to each factor to predict what the factors should have been. xwOBA provides adjusted run expectancies of a batting event in the context of the season as a whole.

Expected values are helpful for fantasy valuations because they hold predictive power for future performance. As we approach the halfway point of the season, it is a good time to reflect on how starters have performed vs. how they were expected to perform. Fantasy managers can take the opportunity to analyze how their teams have performed, where they have excelled, and where they may benefit from trades. Let's use xwOBA to help with this process!

xwOBA Studs for Fantasy Baseball

All stats are current as of Sunday morning, June 11, 2023.

Nathan Eovaldi, Texas Rangers

9-2, 2.49 ERA, .272 xwOBA

This first pitcher has been a fantasy All-Star to this point. Nathan Eovaldi is having a career season, going 9-2 with a 2.49 ERA, 0.98 WHIP, and 24.9% strikeout rate in his first season with the Rangers. He is averaging 6 2/3 IP/GS and has a strong .272 xwOBA to support his performance. Can he keep performing this well for the rest of the season?

Eovaldi has always been a useful fantasy starter, but this season he has taken things up a notch. Looking under the hood, a few things stand out. First, Eovaldi has done a better job with pitch location. He has worked in the bottom of the zone more and has avoided the middle of the plate. Consequently, his expected batting average and expected slugging percentage are in the 70th and 76th percentiles of baseball, respectively, to go with a career-low 4.8-degree launch angle.

He has also switched up his pitch mix. Specifically, he has increased the usage of his split-finger fastball, which was his best pitch last season. His splitter has been his second-most thrown pitch at 26.9% and has yielded a .174 batting average against with an 18.3% swinging strike rate.

Eovaldi has pitched very well to start the season and has carried fantasy managers. He has made some changes, although it seems mostly like he's just gotten his best possible results. Despite his strong expected stats, I wouldn't be surprised to see a little regression toward his career averages. Even if that does occur, Eovaldi should remain a must-start for fantasy managers.

Zach Eflin, Tampa Bay Rays

8-1, 2.97 ERA, .266 xwOBA

When Zach Eflin signed a three-year, $40 million deal with the Rays this offseason, fantasy managers wondered if they could finally convert him into a bonafide fantasy starter. It looks like they have so far, as Eflin has gone 8-1 with a 2.97 ERA, 0.96 WHIP, and 25.7% strikeout rate. His .266 xwOBA supports his performance. What has changed for Eflin?

He has shifted essentially to a three-pitch pitcher this season, relying on his sinker, cutter, and curveball. He has gotten noticeably more spin on his cutter and curve, both of which he has thrown more than last season. His new pitch mix and movement have helped him keep the ball out of the air with a career-low 6.9-degree launch angle. He has also generated a .272 BABIP, the lowest mark since his rookie season.

Eflin has really figured things out on one of baseball's best teams. Both his actualized and expected stats have been stellar as he has focused his pitch mix. With so much inconsistency among starters this season, Eflin has stood out even more as a reliable fantasy option.

xwOBA Duds for Fantasy Baseball

All stats are current as of Sunday morning, June 11, 2023.

Dean Kremer, Baltimore Orioles

6-3, 4.89 ERA, .380 xwOBA

One of the more exciting baseball storylines this season has been the stellar play of the Baltimore Orioles. Dean Kremer has played a part in this, although he has been inconsistent with a 4.89 ERA, 1.44 WHIP, and 19.6% strikeout rate. His .380 xwOBA is in the bottom seven percent of baseball. The O's have played well, but should fantasy managers stay away from Kremer?

Kremer throws each of his three fastball variants a combined 71.1% of the time, and none of them have been particularly effective. His offspeed pitches have not fared much better. Overall, Kremer has allowed a lot of hard contact with a 12.9-degree launch angle, which is not a recipe for success.

It is worth noting that Kremer has gotten better results after a rough April. He has an improved 3.57 ERA through seven starts in May onwards, but he still allowed hard contact in those starts.

I would not trust Kremer in any roto leagues but may consider streaming him in favorable points-league matchups. The evidence supports Kremer's poor xwOBA, but fantasy managers could do worse in streaming situations with such a strong offense behind him.

Yusei Kikuchi, Toronto Blue Jays

6-2, 4.34 ERA, .355 xwOBA

It wouldn't be a fantasy season if we didn't talk about the potential of Yusei Kikuchi. Every season, he seems to be mentioned as a potential fantasy breakout. And every season, he doesn't quite live up to expectations. This season has been no different. While his 4.34 ERA, 1.34 WHIP, and 22.7% strikeout rate are decent, his .355 xwOBA leaves a lot to be desired. Should fantasy managers hold out any hope for him?

Upon initial inspection, there isn't a ton to be excited about. Of his four pitches, only Kikuchi's curveball has been located well with good results. His poor location has led to a lot of hard contact in the air. This has really hurt him in the form of home runs with a 2.44 HR/9 rate and a 21.4% HR/FB rate.

Homers have always been an issue for Kikuchi and nothing currently suggests that they will improve. It all stems from his pitch location or lack thereof, and his expected stats indicate his location has not been where it needs to be. At this point, I would rather stream Kremer than Kikuchi in points leagues.

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