Statcast Pitcher Studs and Duds - wOBA-xwOBA Difference for Week 26

September 24, 2019

Connelly Doan examines the Statcast leaderboard to identify starting pitchers whose wOBA-xwOBA differences did not align with expectations for the 2019 season.

Welcome back to RotoBaller’s pitchers Statcast studs and duds article series for the final week of fantasy baseball! Each week we will select an advanced stat, choose two studs and two duds, and analyze what those stats could mean for future fantasy output.

We have sadly reached the end of the season, so I thought it would be interesting to go back to a metric that I used earlier in the season for it's predictive nature; wOBA-xwOBA. Now that the season is all but over, we can take a look at who ultimately outperformed and underachieved compared to what was expected of them.

Pitchers should perform towards their expected metrics over the course of the season, but it doesn't always line up that way. Identifying players who did not align with their expected metrics should be a fun (or frustrating) way to cap off the fantasy season. So without further ado, let's get started on the last week's article!

wOBA - xwOBA Difference Studs

For reference, the league-average wOBA against is .324 and the xwOBA is .318 (difference of .006). All stats current as of Monday, September 23, courtesy of BaseballSavant.com.

Matthew Boyd - Detroit Tigers

wOBA: .324, xwOBA: .298, Difference: .026

Our first wOBA-xwOBA stud caused quite the ruckus at the beginning of the season due to his hot start and high strikeout numbers. The strikeouts turned out to be legit, as Matthew Boyd has maintained an impressive 30.5% K rate over 181 1/3 innings pitched this season. The other metrics maybe not so much, as his 4.57 ERA and 1.22 WHIP have been mediocre at best. All that being said, the difference between his wOBA and expected wOBA suggests that he has been quite unlucky and should have had a solid wOBA compared to the rest of the league. Let's see if we can pinpoint where the bad luck came in for Boyd.

The interesting thing here is that nothing really stands out as a culprit. Boyd's 1.22 WHIP and 6.4% walk rate are both respectable and in line with his career numbers (1.32 and 7.4%). Further, his .304 BABIP is only slightly higher than his career .296. Looking into his batted-ball profile, his 18.5-degree launch angle is pretty high, but his 88.7-MPH average exit velocity and 35.6% hard-hit rate are middle-of-the-road.

The clear positives of Boyd's season have been his insane K rate (thanks to his filthy slider) and his SIERA; his 3.59 SIERA indicates that he has gotten quite unlucky based on his batted-ball results. The ultimate takeaway here is that, while he should have actually seen better results, Boyd helped out fantasy owners all season long due to his high strikeout numbers. While his current team doesn't help his value, he has shown that he can be relied on as a fantasy asset.

Noah Syndergaard - New York Mets

wOBA: .302, xwOBA: .279, Difference: .023

Our second wOBA-xwOBA stud has been a fantasy stud for several seasons but could only muster average numbers in 2019 despite having an above-average wOBA. Noah Syndergaard has gone 10-8 with a 4.22 ERA, 1.22 WHIP, and 24.1% K rate. Unfortunately for fantasy owners, they almost certainly overpaid for him in single-season leagues. However, for those who have him in keeper or dynasty leagues, his xwOBA gives hope that he can rebound next season. Let's take a further dive into Thor's 2019 season. 

Like Boyd, Syndergaard presents somewhat of a puzzling case. His WHIP and walk rate (6.2%) were respectable and his .308 BABIP was actually slightly lower than his .313 career mark. His batted-ball profile was quite good; his average exit velocity (86.6 MPH) and hard-hit rate (31.9%) are both in the top 17% of baseball. Further, all of his expected stats (batting average, slugging percentage, wOBA) were above average, increasing the evidence for bad luck.

Like the Mets' season overall, things didn't go quite as planned for Thor this season. The good thing is that he showed many signs of still being a higher-end pitcher. I would expect some positive regression for Syndergaard next season and, hopefully, he can give fantasy owners more of what they had hoped for.

wOBA - xwOBA Difference Duds

For reference, the league-average wOBA against is .324 and the xwOBA is .318 (difference of .006). All stats current as of Monday, September 23, courtesy of BaseballSavant.com.

Mike Soroka - Atlanta Braves

wOBA: .270, xwOBA: .304, Difference: -.034

Our first wOBA-xwOBA dud has been excellent this season and is just 22 years old. Mike Soroka has gone 13-4 with an impressive 2.60 ERA, 1.09 WHIP, and 19.9% K rate while pitching to contact. However, his xwOBA, while still quite good, is significantly higher than his actual wOBA. Should fantasy players be worried about negative regression for Soroka next season?

Fortunately, it seems like Soroka's pitching style will allow him to continue to succeed at the big-league level. He relies heavily on his sinker (45.2% usage) and pitches to contact, but has solid control (1.09 WHIP, 5.7% walk rate). Further, his batted-ball profile has the makings of a successful groundball pitcher. Soroka has avoided hard contact (87.2-MPH average exit velocity, 37.9% hard-hit rate) while doing an excellent job of keeping the ball on the ground (5.4-degree launch angle).

The big negative is Soroka's SIERA. His 4.30 SIERA is almost two runs higher than his ERA. While I do feel that is is not realistic to expect a 2.60 ERA from Soroka next season, I also feel that his batted-ball profile is one that will lead to success. Therefore, I am going to overlook his SIERA and say that Soroka will be a higher-end fantasy option next season and for seasons to come in keeper/dynasty leagues.

Yonny Chirinos - Tampa Bay Rays

wOBA: .287 , xwOBA: .316 , Difference: -.029

Our second wOBA-xwOBA dud has served time both as a starter and a "follower" this season, finding success at both. Yonny Chirinos has gone 9-5 with a 3.67 ERA, 1.06 WHIP, and 22.1% K rate over 127 2/3 IP this season. He has been highly useful in fantasy, but does his relatively higher xwOBA suggest that he may regress next season?

Like Soroka, Chirinos relies heavily on his sinker (55.1% usage). However, his stats under the hood do not look as shiny. Chirinos' batted-ball profile isn't bad (87.6-MPH average exit velocity, 33.8% hard-hit rate), but his 10.9-degree launch angle is a little high for someone who relies on thier sinker so much. Further, his .252 BABIP is much lower than his .272 career mark. The Rays are one of baseball's better defensive teams, but that alone does not explain his BABIP. As such, I would be more inclined to believe his 4.21 SIERA.

Overall, Chirinos has been great this season and holds extra fantasy value given his relief pitcher eligibility. However, there is compelling evidence to suggest that he has gotten lucky this season. While he will still be valuable next season, I would not be surprised to see his ERA slide closer to 4.00 in 2020.

More 2019 Fantasy Baseball Advice