Are You For Real? Surprising SP Starts (Week 21)

Welcome to our surprising starts series. Every week we’ll be going over a few surprising starting pitcher performances around the majors to determine whether these starts were smoke and mirrors or something more.

With the season winding down there aren't as many waiver wire options that haven't already been covered, and boy was there a dearth of good starts to choose from this week.

Normally three pitchers are covered in this article, but quite frankly there weren't three surprising starts last week that warrant consideration. So instead this article is going to break down two sides of an unexpected pitcher's duel between Alex Cobb and Adam Plutko last Saturday.

Alex Cobb, Baltimore Orioles

2018 Stats (prior to this start): 123.2 IP, 5.31 ERA, 4.68 FIP, 2.6 K/BB ratio

08/18 @ CLE: 9 IP, 5 H, 2 ER, 1 BB, 3 K

Cobb was covered in this series all the way back in May, and while there was reason for optimism at the time, it was clear that Cobb wasn’t back to his pre-Tommy John levels. Things were rough for him for about two months after that start against the Athletics. He suffered through 62.2 innings of a 6.32 ERA between May 9 (the day after that article was published) and July 12. Why July 12? Well, that’s the day before Cobb began a six start stretch with a 2.14 ERA and 3.1 K/BB ratio. His most recent start was the best of all, a two-run complete game against the Cleveland Indians. The Indians are one of the best teams in the majors offensively with a .331 wOBA and 107 wRC+ against right-handed pitching this season. They are without Edwin Encarnacion right now, but Cleveland is a formidable lineup nonetheless.

So, what exactly changed for Cobb to go from one of the worst pitchers in baseball to shutting down the Indians? Well, for one thing he is leaning on his vaunted splitter more heavily. Here is a graph of monthly pitch usage for Cobb this season (source: brooksbaseball.net).

He is up to 39.8% usage in August, which has also been his best month by far performance-wise. He has a 1.55 ERA and his splitter has a .167 BA against with a 16.88% whiff rate. In a season filled with home runs and heartache Cobb’s splitter has been the lone bright spot. To get an idea of where Cobb is with his splitter right now relative to his prime with the Rays and earlier in the year we’re going to compare three separate splitters.

Here is one from 2013:

Here’s one from that start in May against the Athletics:

And here is one from this last start:

The pitch from his most recent start looks closer to his peak than the one from three months ago. It has gained three inches of drop over the course of the year and has better horizontal movement. The pitch from his start against Oakland had decent drop but was much straighter than the prime version of Cobb’s splitter or even the one from his start against Cleveland. Based on recent trends Cobb’s splitter looks to be a plus pitch again, and the return of his splitter is the single most important thing for Cobb on the path to becoming a good pitcher again.

There are a few reasons to be skeptical of Cobb’s recent performance. First, he still only has a 15.4% strikeout rate over this hot stretch. Whiffs are up on his splitter, but because he isn’t throwing his four-seamer fastball anymore Cobb’s overall strikeout rate hasn’t improved and it’s seems unlikely that much growth is coming in that category. Cobb is also riding a .266 BABIP over this seven-start stretch. There are two encouraging trends when we look at his 15-game rolling averages in batted ball data (source: fangraphs.com).

He lowered his hard contact rate by 8% and his line drive rate by 3%. Like the improvements with the splitter this is a step in the right direction for Cobb, but he’s still not the Alex Cobb of old.

In fairness to Cobb it might be unrealistic to expect him to return to his pre-Tommy John levels of production. He’ll be 31 in October and the layoff cost him two years of his prime. It’s not his fault he suffered the injury nor is it his fault the Orioles overpaid him. Alex Cobb may just be a low-dominance groundball pitcher with a really good splitter. That doesn’t make him a must start pitcher, but it does make him a fine streamer or back-end starter.

Verdict:

Cobb’s splitter has a little more zing than it did three months ago, and bit-by-bit he seems to be improving. He may never return to the top-25 level that we once dreamed for with him, but that doesn’t make the current iteration of Cobb unusable. He’s a viable streamer down the stretch. He’s hard to trust in his next start Wednesday against the Blue Jays, who have a .322 wOBA and .178 ISO against right-handed pitchers this season.

Adam Plutko, Cleveland Indians

2018 Stats (prior to this start): 41.2 IP, 4.75 ERA, 6.00 FIP, 2.6 K/BB ratio

08/18 vs. BAL: 7 IP, 3 H, 3 ER, 1 BB, 6 K

With Trevor Bauer sidelined the Indians will have to rely on Plutko as their fifth starter. Looking at their organizational depth they don’t have any fallback options if Plutko doesn’t work out. Danny Salazar and Cody Anderson are both out for the season. They do have Josh Tomlin on a rehab assignment, but they might as well start a pitching machine at that point. It looks like the Adam Plutko show in Cleveland every fifth day, and while he has been rather atrocious this season he did show up for this game with the Orioles, though he was outdueled by Alex Cobb. Whenever a widely available pitcher gets falls into guaranteed starts with one of the best teams in baseball he’s always worth a look.

Plutko has a four-pitch repertoire consisting of a four-seam fastball, a slider, a changeup, and a curveball. His fastball is a rather pedestrian offering at 91.8 MPH, while his slider has proven the best offering in terms of BA against (.200) and whiff rate (15.8%). Plutko got ten whiffs in this start, five on his fastball, three with his slider, and one each with the changeup and curveball. He mostly throws the fastball and slider, using the two pitches a combined 81.5% of the time. While Plutko’s slider should be considered his best pitch, it isn’t a particularly good slider. It has below average drop and whiff rate. A good whiff rate on slider should be ~19% or higher, so 15.8% is nothing special. The pitch was quite hit-or-miss in this start. Here are examples, a good one and a bad one.

Yikes. In one way that pitch was actually so bad it was good. Plutko was going for the low and away slider, but missed so poorly that all Renato Nunez could do was chop it down the line for a double. If that pitch was an inch or two lower it would’ve been the easiest home run of Nunez’s career. Don’t worry, Plutko made up for it by surrendering a three-run homer the next inning.

That pitch did what Plutko intended on the cookie to Renato Nunez. It spun outside and was in the dirt low and away. All Mark Trumbo could do was give a half-hearted I’m-horribly-overpaid swing at it. Even the slider at its best doesn’t exactly blow anyone away. Command is going to be very important for Plutko. It’s important for every pitcher, but for pitchers with underwhelming stuff like Plutko it’s even more important. There’s a reason he’s given up 12 homers in 48.2 innings. Poor stuff plus poor location equals big fly. He doesn’t have poor control, as evidenced by his 6% walk rate, but he seems to have troubling locating his pitches. A more tangible way to look at this is by taking a peek at his slider heatmap.

That’s way too much zone to feel comfortable. Being on the Indians should net him a few wins, but it will come at the cost of poor ratios and a mediorce strikeout rate. ERA predictors peg Plutko as a pitcher that will have an ERA north of five, and it’s easy to see why.

Verdict:

Underwhelming stuff, poor command, and chronic gopheritis. But hey, he might get a few cheap wins on the Indians. His next start comes Wednesday at Boston, and that’s a Heck No with a capital H and a capital N.

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