Strikeout Rate Risers and Fallers for Week 11: Buy or Sell?

Due to a combination of harder throwers and hitters focusing on hitting for power, strikeouts are at an all-time high in baseball. For pitchers, this is an ideal trend. The ability to generate swings and misses is the most important skill to possess, as it's the only true way to control what happens after the pitch is thrown and eliminate the randomness that the ballpark, fielders, weather, and luck can play.

The stat is equally important for fantasy players. Not only are strikeouts a category in every league, but K-rates are often indicative of overall production. A pitcher with a 4.50 ERA with a 25.0 K% may see some positive regression in the future. On the other hand, a hurler with a 3.00 ERA and 16.0 K% may not see the ball continue to bounce their way.

In this column, we'll review two strikeout rate risers and fallers to determine if their performance will improve, hold steady, or worsen as the season moves along.

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Risers

Jhoulys Chacin, Milwaukee Brewers

2018 K-Rate: 18.0%; Last 30 Days: 23.7%

At various times in his career, Jhoulys Chacin has proven to be a valuable fantasy arm (3.91 ERA) despite unexciting strikeout numbers (18.4 K%). His 2018 performance is right on par with his career numbers, as he currently boasts a 3.58 ERA and an 18.0 K%. With a strong offense to support him, Chacin has been a decent pickup in deeper leagues. But his pitch-to-contact approach limits his overall value, and his peripheral numbers (4.82 xFIP, 4.81 SIERA) indicate regression is coming. His recent uptick makes him a more attractive fantasy option, but can it last?

The first sign to look for is whether Chacin is getting significantly more swings and misses rather than relying on called strike threes. In the last 30 days, spanning six starts, the right-hander has seen his SwStr% rise to 10.3% from 7.2% in is first seven starts of the season. In other words, he's gone from poor to average at getting whiffs. Hitters have also managed a 76.0% contact rate against him during this stretch, down notably from 82.9% in his first seven outings. While the whiff percentage on each of his pitches has increased — significantly for his changeup, curveball, and four-seamer — there hasn't been any discernible difference in pitch mix, velocity, or arm angle; Chacin is simply commanding the ball better, painting the corners of the plate more often instead of leaving the ball right down broadway.

He's also following the growing trend of turning to his best pitch more often. Chacin upped his slider usage significantly in 2017 and that has continued this year, as it's now his primary offering. Only five qualified pitchers spin their slider to the plate more often than Chacin, who has used it 37.7% of the time. While the pitch isn't as dominant from a whiff perspective (14.1 SwStr%) as it once was, it has held batters to a .187 slugging percentage. Per FanGraphs' pitch value, Chacin boasts the fourth-best slider in the game in 2018.

Still, these improvements don't necessarily lend themselves to maintaining a high strikeout rate the rest of the season for Chacin. His fastball/sinker velocity is still below average, and he doesn't get hitters to chase outside the strike zone often (26.6 O-Swing% vs. 30.2% league average). While his slider is a solid swing-and-miss offering, it's far from elite, and he doesn't use his changeup or curveball enough for them to be huge weapons. Chacin is also giving up a lot of walks (9.5 BB%), and his hard-contact rate (39.8%) is alarming. He may maintain an average strikeout rate, but these red flags prevent him from being a true fantasy commodity in all but deeper mixed leagues. If you can sell him while he's hot, do it.

Jameson Taillon, Pittsburgh Pirates

2018 K-Rate: 22.7%; Last 30 Days: 26.4%

Earlier in the season, Jameson Taillon appeared in the "Fallers" portion of this column when he stumbled in late April and early May after a hot start. His high strikeout totals in his first three outings of the season seemed more fluky than anything else, as he didn't have a go-to out pitch to complement his mid-90s fastball. Now he does. The right-hander began to feature a slider in mid-May, and it could be the weapon he's needed to unlock his full potential.

As the chart below shows, Taillon hasn't been shy about throwing his new pitch, making it his most-trusted secondary offering almost right off the bat:

It has paid immense dividends for him. The slider boasts a 19.1 SwStr% and a ridiculous 54.0 O-Swing% as batters are offering at the pitch 60.7% of the time they see it. Those latter numbers may come down as the book gets out on Taillon's slider, but it's clearly a plus offering for him already. The pitch comes in at an average of 89.7 mph, looking much like his fastball until it drops off the table. As more teams gear up for the slider, his fastball is fooling more hitters as well.

Taillon toyed with the pitch on May 22 against the Cincinnati Reds before fully unveiling it in his next start against the St. Louis Cardinals on May 27. In his three starts since then, Taillon has posted a 2.79 ERA and struck out 19 batters in 19 1/3 innings. His SwStr% is 11.0% in that time, up from 9.2% in his 10 previous starts. The slider has his groundball rate trending upward as well, with the pitch getting hit into the dirt 57.1% of the time. If Taillon's slider continues to be this effective, it could be the key to becoming the top-of-the-rotation arm the Pirates hoped for when they drafted him second overall eight years ago. Now is the time for fantasy players to buy the right-hander.

Fallers

Trevor Cahill, Oakland Athletics

2018 K-Rate: 25.0%; Last 30 Days: 16.7%

After splitting his time between starting and relieving for most of the past four seasons, Trevor Cahill re-emerged on the fantasy scene early in 2018 after a hot start. In his first four outings back with his original team, he posted a 2.25 ERA, an elite-level strikeout rate of 33.7%, and a 16.0 SwStr%. Then, as has been a problem for him in the past, he got injured, landing on the disabled list with an elbow impingement. He only missed a week-and-a-half of action and has a solid 3.28 ERA since, but the strikeouts are down.

With only 16 strikeouts in his last 24 2/3 innings, his whiffs have naturally dropped, sitting at a 10.3 SwStr% since his return from the DL. The changeup and curveball have faltered the most, with the former falling from an elite 28.7% whiff rate to 21.4% and the latter dropping from 20.7% to 7.1%. His four-seamer and sinker whiff rates have also decreased, and batters are making contact on 76.7% of swings against him — a far cry from the 63.8% he posted in his first four starts.

But it isn't all bad news. His slider, which he reintroduced last season after largely scrapping it earlier in his career, is becoming a real asset. Over his last four starts, it has registered a whiff 16.3% of the time, up from 9.8% in his first four starts. Last season, the breaking ball sat at an impressive 20.2 SwStr%. Additionally, he's using it more over the last month, as it's become his go-to secondary pitch along with his changeup. Cahill is also still getting hitters to chase out of the zone at an above-average rate. Although his whiffs and strikeouts are heading in the wrong direction, the change in O-Swing% has been minimal (32.4% pre-DL, 31.6% post-DL).

While Cahill probably isn't a 30 K% pitcher all of a sudden at age 30, he has shown a strong ability to punch out hitters in the last two seasons, with a 23.2 K% in 2016 and 22.8% last year. His changeup, while not quite as dominant as it was earlier in the season, is a plus pitch, and his blossoming slider is starting to round into form. On top of that, he also has the lowest walk rate of his career (5.9%). That being said, Cahill is giving up a ton of hard contact (44.9%) and no starting pitcher has generated less soft contact (10.2%), so his success is less likely to last if the strikeouts stay down. He's a pitcher to hold for now, but he may be worth flipping if you can get a more proven commodity for him, especially with his injury history.

Sean Newcomb, Atlanta Braves

2018 K-Rate: 24.2%; Last 30 Days: 17.5%

Like many young Braves players, Sean Newcomb has started to come into is own in 2018. The former highly touted prospect owns a 2.49 ERA through his first 12 starts of the season, he's getting a ton of groundballs (50.6%), and his strikeout-to-walk ratio has improved (12.5 K-BB% vs. 11.2% in 2017). Since allowing five earned runs in his first start of the year, the southpaw has allowed more than three runs only one time. Lately, however, the strikeouts have gone missing. In Newcomb's last four outings, he has 14 strikeouts in 22 innings, which paints a murky picture when paired with his ongoing control issues.

Will Newcomb's strikeout rate return to its early-season surge? The underlying numbers don't seem to be in his favor. His 10.2 SwStr% on the season is well below his rate from last year (11.1%), when he struck out batters at a lower rate (23.7%). The 24-year-old was touted for having a plus curveball during his time as a prospect. Although hitters have done virtually nothing with it when they put it into play (.088 slugging percentage), that hasn't translated to a high whiff rate at the big-league level. In 2017, the hook was good for a solid but unspectacular 13.5 SwStr%. This year, that number has dipped to a disappointing 8.6%. Newcomb has developed a decent changeup, but its effectiveness at missing bats has also diminished. It currently sits at a 13.4 SwStr% after an impressive 19.6% mark in his rookie campaign. Over his last four starts, it has a measly 9.8% whiff rate.

Newcomb is also struggling to get hitters to swing outside the strike zone (27.2 O-Swing% in his last four starts vs. 30.2% in his first eight), and his overall control problems may be playing a role in that. Among qualified pitchers, only Lance Lynn and Aaron Sanchez have a worse walk rate than Newcomb (11.7%). He struggles to get ahead early in the count, with his first-pitch strike rate (56.9%) ranking 13th-worst in the league. Lately, that problem has become worse, as he has a F-Strike% of 51.7% in his last four outings.

With a fastball that can reach the upper-90s, Newcomb has a wealth of potential. His inconsistency with pounding the strike zone and the lack of a strong putaway pitch, however, limit his strikeout upside right now. Fortunately, he gets a lot of groundballs (50.6%) and prevents hard contact (27.8%), which have kept his ERA from ballooning. The way he's walking people is also playing with fire, though, which his 4.00 xFIP and 4.24 SIERA indicate. Newcomb is a must-own player in dynasty leagues, but those in mixed leagues should prepare for regression if current trends continue.

All stats as of Sunday, June 10.

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