Statcast Pitcher Studs and Duds - Advanced Metrics Leaders for Swinging Strike Rate (Week 9)

May 22, 2023

Connelly Doan examines fantasy baseball pitcher risers and fallers, and whose swinging-strike rates could make them adds, drops, or trade targets for Week 9.

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. An important facet of pitchers' profiles for fantasy baseball we haven't yet looked at is the swinging strike rate (SwStr%).

SwStr% is the percentage of pitches a hitter sees that they miss (or the percentage of pitches a pitcher throws that induce swinging strikes). It is not as directly applicable of a metric as strikeout rate to fantasy production because strikeouts hold direct fantasy value, as opposed to missed strikes in general. However, pitchers are generally more likely to succeed if they can miss bats and keep the ball out of play. Further, pitchers who can miss bats can generate more strikeouts.

Pitchers can be valuable in fantasy by pitching to contact, but those with strong SwStr% have an advantage. Identifying pitchers who can consistently miss bats is a sound way to hunt for fantasy value. Without further ado, let's take a look at some SwStr% starting studs and duds!

SwStr% Studs for Fantasy Baseball

All stats are current as of Sunday morning, May 21, 2023.

Sandy Alcantara, Miami Marlins

1-5, 5.05 ERA, 22.6% Strikeout Rate, 14.1% SwStr%

One of the biggest surprises in fantasy to this point has been Sandy Alcantara's poor start. The 2022 National League Cy Young winner has struggled heavily with a 5.05 ERA and 1.23 WHIP in his first nine starts. Confusingly, one facet of his game that has improved is a jump in SwStr% to 14.1%, which is one of the highest marks among qualified starters. What should fantasy managers make of him?

In terms of his SwStr%, Alcantara has actually seen an increase for all four of his pitches. The two biggest jumps have come in his four-seam fastball from 10.6% to 13.8% and his slider from 14.8% to 18.4%. His velocity and movement profiles for both pitches are almost identical to last season's, so I'm not convinced that these jumps will sustain. Alcantara has always had great stuff but has never been a high-end fantasy strikeout option, and I don't expect that to change.

The issue for Alcantara this season has been his third time through the order. He is known for pitching deep into games, and his first two times through the lineup this season have looked like the same old Alcantara. However, the third time has been an absolute disaster, with an ERA of 13.14 compared to 3.41 in 2022.

Alcantara has gotten increased swings and misses so far, but hasn't done much else. I think his SwStr% will return to his career average over the course of the season given the similarities in his pitches from last season. However, I also think his numbers will come back to what fantasy managers expect. His bloated ERA towards the end of his outings stands in such contrast to the beginnings of his starts that I don't think they will persist.

Alcantara was an early fantasy pick, so fantasy managers are likely holding onto him as they should. On the flip side, it doesn't hurt to try to buy low on him for fantasy managers who may be frustrated and nervous with his early-season woes.

Luis Castillo, Seattle Mariners

2-2, 3.31 ERA, 27.8% Strikeout Rate, 13.9% SwStr%

Luis Castillo has quietly moved up fantasy rankings over the past several seasons and has gotten off to a good start overall, going 2-2 with a 3.31 ERA, 1.05 WHIP, and 27.8% strikeout rate. Further, his 13.9% SwStr% is solid and among the best marks for starting pitchers. Can Castillo maintain his steady climb?

His SwStr% this season is exactly in line with his career mark of 13.8%. Castillo has relied much more on his four-seam fastball this season. The pitch is solid with a 15.2% SwStr%, although he has seen a dip in velocity on all of his pitches. He has relied least on his best swing-and-miss pitch, his changeup. He has only thrown the pitch 16% of the time despite a 16.4% SwStr%.

There are some additional noteworthy underlying signs. First, Castillo's batted-ball profile is not as encouraging as it has been in the past. His exit velocity and hard-hit rate are both in the bottom 15 percent of baseball to go with a career-high 16.5-degree launch angle.

His batted-ball profile seems to have caught up to him in May. Castillo has a 6.35 ERA and 1.29 WHIP in his last three starts. The strikeouts have been there (27% strikeout rate, 13% SwStr%), but the overall results have not been.

Pitching in general has been frustrating so far this season, and Castillo has not been an exception. His strikeout numbers have been what fantasy managers have expected despite relying more on his four-seamer and less on his changeup. His batted-ball profile has been worrisome and has started to catch up to him. All pitchers go through rough patches, but I would be worried if Castillo continues to get hit this hard.

SwStr% Duds for Fantasy Baseball

All stats are current as of Sunday morning, May 21, 2023.

Alex Cobb, San Francisco Giants

3-1, 1.94 ERA, 20.4% Strikeout Rate, 7.9% SwStr%

Alex Cobb has been a useful fantasy starter over the past several seasons and has gotten off to a great start this season with a 1.94 ERA and 1.35 WHIP through nine starts. One weak spot has been strikeouts. Cobb has never been a huge strikeout pitcher, but his strikeout rate has dipped to 20.4% with a 7.9% SwStr% compared to 10.4% last season. Should fantasy managers be wary of overperformance?

As I mentioned at the top of the article, pitchers can be successful by pitching to contact and Cobb is an example of this. Cobb is a groundball pitcher, relying mainly on a sinker and split-finger fastball. He pitches to contact, which raises his WHIP some. He has also allowed hard contact, but his -0.5-degree launch angle helps him limit damaging contact.

In terms of his SwStr% drop, the splitter is the main culprit. The velocity has been similar to last season, but the pitch movement has traded vertical drop for a horizontal break. Consequently, his SwStr% on the pitch has dropped from 16.2% to 10.7%, his chase rate has dropped from 42.9% to 37.4%, and his contact rate has risen from 71.4% to 81.1%.

Fantasy managers have never expected huge strikeout contributions from Cobb, but his splitter changes have dented them even further. On the greater plus side, he has been a great overall fantasy contributor and should continue to do so by keeping the ball on the ground.

Anthony DeSclafani, San Francisco Giants

3-3, 3.09 ERA, 18.7% Strikeout Rate, 7.9% SwStr%

Cobb's rotation mate has also gotten off to a solid start. Now healthy, Anthony DeSclafani has looked like he did in his first season with the Giants, going 3-3 with a 3.09 ERA and 0.99 WHIP in nine starts. Like Cobb, DeSclafani has never been a huge strikeout pitcher, although his 7.9% SwStr% is a career low. Can he still be a useful fantasy starter?

Nothing really stands out one way or the other. DeSclafani's batted-ball profile is about league average with a 7.9-degree launch angle. His 4.05 SIERA is higher than his ERA, but he does benefit from pitching his home games in Oracle Park.

His decreased SwStr% could have to do with his pitch location. Most of his pitches have focused in the top-middle portion of the zone, which has not made it hard for hitters to find contact. DeSclafani's 83.2% contact rate is among the highest for qualified starters. This isn't necessarily a bad thing, but he is not a groundball specialist like Cobb.

DeSclafani has pitched to more contact than usual this season and has still gotten pretty good results. However, regression could be coming for him if he continues to throw all his pitches in the sweet spot of the strike zone. For now, I think he is a serviceable back-of-the-rotation fantasy starter in all leagues with the opportunity for some strikeout improvement if he can slightly improve his pitch location.

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