The Z Files: Six Underperforming Arms

For those keeping score at home, three of the five subjects of last week's piece hit the IL since posting. This time, I'll be evaluating six more pitchers so apologies in advance if any suffer the same fate. Though, since the topic will be underperforming arms, perhaps a thank you will be in order.

If you recall, last week Matthew Boyd, Danny Duffy, Taijuan Walker, Huascar Ynoa and Kyle Gibson were dissected here and by the Tout Wars participants in a Tout Table. This time, we're running it back from the opposite angle:

Which of this six are you most looking to acquire and who do you want no part of the rest of the season among Luis Castillo, Patrick Corbin, Dylan Bundy, Kenta Maeda, Kyle Hendricks and Charlie Morton?

I'll be posting the replies Friday with Castillo the overwhelming clubhouse leader for the first part of the question. The second one has generated varying replies. As I did last week, I'll put the subjects under the microscope to ascertain my own response. The query was initial made Tuesday afternoon, so several of the hurlers have toed the rubber since, most with encouraging results.

As discussed last time, while comparing current ERA to its estimators is an integral aspect of the analysis, it's not the sole component. Nevertheless, it's a good jumping off point. All statistics are current through Thursday, May 20, 2021.

Luis Castillo, Cincinnati Reds

Castillo has been unlucky: blah blah blah, woof woof woof. There has to be more to it than that, right?

Clearly, his swinging strike mark is down. Is there a most guilty pitch or are there multiple offenders? First, here is a look at his arsenal.

Now the swinging strike mark for each.

Assuming last season's mark on the four-seamer was an outlier, Castillo's changeup appears to be the biggest issue.

Anecdotally, some feel Castillo is a warm-weather pitcher and just needs the mercury to rise. However, there is another possible explanation related to the 2021 baseball. Most of the talk is of how the slightly raised seams are inducing more air resistance, thereby reducing flight. Could the higher seams also be affecting Castillo's ability to grip and throw his changeup? If so, it could be reflected in the velocity and spin numbers, keeping in mind spin is generally bad for a changeup as gravity is designed to do the work.

The spin rate is indeed higher, but I'm not knowledgeable enough in this realm to contend this is enough to make a difference.

What about Castillo's changeup location?

Unfortunately, there isn't anything glaring here either.

Confession time: there is another level of analysis possible, but I'm simply not comfortable going down that road since I'm unclear on the application and what the numbers mean. Specifically, horizontal and vertical movement can be measured, with and without the effects of gravity. I have the data but am unsure how to interpret it. The problem is the numbers are a bit different this season so it may hold the key. Perhaps it's my scientific nature, but I don't just combine the contents of two beakers without having a very good idea what will happen.

So, without knowing the next-level cause, the question with Castillo is whether he'll regain his usual effectiveness on his changeup.

Patrick Corbin, Washington Nationals

Too many homers are obviously driving Corbin's first-quarter plight. Let's check in on his other skills.

By the looks of this data, last season was a true decline for Corbin, and he isn't demonstrating the ability to revert to pre-2020 form. By means of reminder, here are his final digits from last season, albeit in just 11 starts.

Corbin's xFIP and SIERA are similar this season and last, so maybe this is his new baseline and once his homers settle, the lefty will pitch to an ERA a bit north of 4.00.

Before dropping the mic, is there a reason for the decline the past two seasons and is it rectifiable?

Let's cut to the chase. Corbin relies heavily on his slider, throwing it around 40% of the time. It's velocity and spin rate both dropped last season and are similar so far this year.

If you believe Corbin can recapture his slider, he's a good buy low. He's just 31 years old, so that isn't an issue. However, he threw 657 1/3 regular season innings from 2017-2020, the fifth most in MLB. That is a lot of sliders, and a lot of wear and tear on his left arm.

Dylan Bundy, Los Angeles Angels

Sure, Bundy's BABIP and HR/FB are a tad high, but they're well within standard range. His bugaboo has been an inability to strand baserunners. Keep in mind LOB% is independent of the level of traffic. That said, Bundy's 1.27 WHIP is a smidge above what you'd like to see.

It's important to understand the application of LOB%. In short, it highlights how many runs should be scored based on the runners allowed. Bullpen efficiency can have an influence, but timing of hits is far more important. For instance, giving up exactly one hit an inning over six frames is usually referred to in positive terms as scattering a half dozen hits. However, if three or four occurred in one inning, resulting in multiple runs, it's a different story. Obviously, how well the pitcher locates, etc. helps keep hits down, but there is also a certain element of timing (dare I say, luck) involved. Yes, better pitchers get out of jams, but if there is luck involved on the fate of a batted ball, there is also luck relating to whether someone is on base. Another factor is the number on base for a home run. It can be argued the pitcher was a bit unlucky when he surrendered a three-run shot compared to a solo dinger. Again, this isn't completely luck-based, but it is a factor.

The average LOB% is around 72 percent and most pitchers cluster at that level. Superior arms can maintain a LOB% up to 78 percent. Above 78 percent likely has an element of good fortune, while below 70 percent suggests a snake-bit hurler. Bundy's 57.2 percent mark is indicative of some serious misfortune.

As stated, there is likely more than luck involved. Bundy is not helping himself out. More walks and fewer strikeouts could be a reason, but his K-BB% is the second highest of his career.

To be fair, before his last two outings, Bundy's 4.00 ERA and 1.08 WHIP were far more palatable. The righty happened to run into the Dodgers and Red Sox in his most recent efforts, in which he allowed 13 runs over 7.1 combined innings, allowing 13 hits and five walks with only six punchouts.

Kenta Maeda, Minnesota Twins

Clearly, Maeda checks all the "unlucky" boxes. However, an ERA around 4.00 is at least half a run higher than expected by those who invested significant draft capital in him this spring. There must be more to his early-season woes.

Yikes! Granted, last season will likely go down as the outlier, but even though Maeda didn't have to face a designated hitter in 2018 and 2019 while also pitching in a great venue at home and shifting to the bullpen late in the season, his skills decline is jarring.

According to Fangraphs pitch values, Maeda's curve is his only pitch anywhere close to useful and he only throws it 3 percent of the time. His pitch mix is similar to last season as is his velocity. Location is different, but is it sufficient to account for the huge discrepancy in results from past seasons?

The middle third is where you don't want to be, so perhaps Maeda's command is the main culprit.

Out of curiosity, I checked out how much rest he's getting between starts. Last season, Maeda worked on five days rest most of the truncated campaign. So far this year, his outings have come with 5, 6, 6, 5, 5, 7 and 4 days rest. He's lined up to take the hill Saturday with five days of rest. One plausible explanation for his decline is an inconsistent schedule that has inhibited the former Dodgers swingman from finding his rhythm. Another possibility is Maeda is pitching through an injury, especially considering the recent report he dealt with mild groin soreness in his last effort.

To be truthful, Maeda has me flummoxed. Maybe friend and colleague Jason Collette can shed some light, as his latest Collette calls is What's Wrong With Maeda?

Kyle Hendricks, Chicago Cubs

Like Maeda, Hendricks hit every branch on the way down as he fell from the bad luck tree. Also like Maeda, his expected ratios still pale in comparison to initial expectations. However, Hendricks' other peripherals are in line with his track record.

OK, maybe his strikeouts are down a tad, but everything is within a reasonable range. Let's not waste too much time here. There doesn't appear to be anything wrong with Hendricks. His lack of dominance renders him more subject to batted-ball whims than those hurlers who rack up whiff after whiff. Regression doesn't punch a time clock, and it's usually on the other end of this discussion. Hendricks should be fine, with the caveat in his case that 'fine' comes with limited strikeouts and he's still a candidate to incur further volatility on balls in play.

Charlie Morton, Atlanta Braves

It's evident Lady Luck has also slighted Morton, putting his league managers in a salty mood. Skills-wise, Morton is in good shape.

The main difference between Morton and the others is he's older with a checkered injury history. Keeping in mind this was a Tout Table question, his inclusion was a means of gauging how my brethren factored health risks into the equation.

Summary

As revealed in the beginning, the Touts overwhelmingly identified Castillo as the arm they want to acquire. I have no reason to dispute that conclusion, but I'll add I have no issue pursuing Bundy either, as I see him just as likely to rebound.

Really, I'm good with going after all of the subjects, though I am most concerned about Maeda. I share my colleagues' opinion on Corbin too, but there's still a chance he either figures out what is wrong with his slider or comes up with another means of retiring hitters. There is just too much unexplainable wackiness with Maeda, compounded by the very real chance we all expected too much. Perhaps he benefited more than accounted for by regional play last season in the softest geographical zone.

With respect to Hendricks, reversion to strong ratios is likely, but as suggested, he still carries risk. Not to mention, his low strikeout totals require stellar ratios to be most useful. The notion with Hendricks is he buffers management of other pitching roster spots, helping to make up for his paucity of punchouts.

Finally, there is tangible risk with Morton, so while I like the chances for his ratios to revert to normal, I'm not going to pay full freight to acquire his fantasy services. If I can talk my trading partner into an injury discount, though, I'm all over him.

Please be sure to check out the Touts responses to this inquiry on the Tout Wars site.