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.

This week we're looking at a pair of NL East hurlers that have put up some eye-popping strikeout numbers, as well as an unheralded NL Central starter.

Phillies starter Nick Pivetta headlines the article this week. He has carried over his strikeout numbers and corrected many of his flaws. Caleb Smith and Trevor Williams are the other two worth a look as each turned out good starts on Sunday.

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Real Deal or Mirage?

Nick Pivetta, Philadelphia Phillies

2017 Stats: 133 IP, 6.02 ERA, 4.87 FIP, 2.46 K/BB

04/22 vs. PIT: 6.1 IP, 5 H, 2 ER, 2 BB, 7 K

Pivetta is someone that could have made this list several times over the past few weeks. His overall line of a 2.57 ERA, 2.26 FIP, and 7.00 K/BB make him look like an early season breakout. There were also some signs that Pivetta was unlucky last season. He had a .332 BABIP against, a 67.1% strand rate, and 18.2% HR/FB. That is the trifecta of pitcher bad luck. Through his first five starts Pivetta has curbed his two biggest flaws last season, the walk and the long ball. Pivetta has lowered his walk rate from 9.8% to 3.6% and lowered his HR/9 from 1.69 to 0.32.

Pivetta has made a change we’ve seen many pitchers make this season. He has lowered his fastball usage and upped his breaking ball usage. Pivetta has two plus breaking balls, a curveball and a slider. He also has a four-seamer that averages about 95 MPH but can top out around 97 MPH. Pivetta has begun to use his curveball nearly 25% of the time. Not only has Pivetta used his curveball more, but it’s been a better pitch. It has four more inches of downward break compared to 2017. Here is a side by side comparison of the curveball from 2017 (top) to 2018 (bottom).

It breaks more sharply and more drastically downward. What this change has done is fostered his slider’s strikeout ability. Pivetta has a 25.40% swinging strike rate with his slider, up from a career 19%. By mixing in his curveball more batters are being fooled by his slider, a faster breaking ball. That’s exactly what Pivetta did in his start against Pittsburgh, as he had 13 swinging strikes, including seven with his slider.

This approach should help correct a major issue that Pivetta had last season, which was reverse splits. Right-handed batters had a .409 wOBA and 2.69 HR/9 against him. Right-handers really took advantage of Pivetta’s curveball, hitting .286 with a .306 ISO. This season righties are hitting .125 against the pitch with a .250 ISO. Using more breaking balls may have the unfortunate side effect of giving Pivetta large traditional splits. Lefties are hitting .417 against the curveball this season, though it’s too small of a sample size to make a judgement either way. It’s something to watch for as the season progresses, because we must be wary of a pitcher that struggles against lefties in the NL East.

Pivetta has a bad habit of hanging the curveball, and in this start against the Pirates it’s exactly how he gave up runs. He hung a curveball to Jordy Mercer for a double, and then immediately hung another to Elias Diaz for a two-run home run. Even though that home run to Diaz was the first Pivetta has allowed all season, we can’t buy into his home run suppression. Pivetta has a 4.2% HR/FB ratio and his home ballpark had the highest home run factor (1.409) last season. There is no reason to believe his 0.32 HR/9 is realistic, and it would be surprising to see him maintain a HR/9 below 1.00.

Verdict:

Pivetta has made strides with his breaking ball. Both the slider and curveball have increased usage, movement, and effectiveness. Expect a high strikeout rate, but home runs may be an issue for him. He is someone that can be more than a streamer and should be picked up, but be careful against teams with lots of power hitters or teams that handle curveballs well.

Caleb Smith, Miami Marlins

2017 Stats (w/ NYY): 18.2 IP, 7.71 ERA, 5.62 FIP, 1.80 K/BB

04/22 @ MIL: 6 IP, 2 H, 2 ER, 0 BB, 10 K

Smith’s 2018 stats look a lot like Pivetta’s 2017 stats. He has a juicy 13.29 K/9, but it comes with a 5.82 ERA, 1.66 HR/9, and 6.23 BB/9. Even at his worst Smith strikes people out. He hasn’t had a K/9 lower than 11 in any of his starts, even though he’s gotten bombed in some of them. The best comparison for Smith is a left-handed, even more rocky version of Dinelson Lamet. Smith’s stuff isn’t nearly as good as Lamet’s, but they profile similarly. Smith relies almost exclusively on two pitches, his 93 MPH four-seamer, and his 82 MPH slider. He has a show-me changeup, but he has thrown either his fastball or slider 89.1% of the time. The slider has been lights out through five starts. Batters are hitting just .088 with a.029 ISO against the slider, and whiff 20.74% of the time. His fastball hasn’t fared as well, as batters are demolishing the four-seamer for a .326 average, .372 ISO, and all four of Smith’s home runs allowed have come on fastballs. What that leaves us with is a two-pitch pitcher with one good pitch.

In the two starts where Smith really got shelled (5 ER in 2.1 IP@ NYY, 3 ER in 3 IP @ PHI) he struggled with slider command and walked 11 batters in these two starts. He also threw his changeup the most in these two starts, using it 15.5% of the time in these outings while using it just 7.3% of the time in his other three starts. When his slider isn’t working Smith goes to the changeup, and it has not been pretty. The changeup has an 18.18% whiff rate itself along with a .167 average against, but he’s only thrown it 44 times and it’s more of a fallback option than a regular part of his repertoire. What those two disasters show us is that Smith can't survive without his slider and this is the consequence of poor command and a limited arsenal.

Smith’s start against Milwaukee is an example of what can happen when his slider is on. He got seven whiffs with the pitch and 12 total. Most encouraging, he didn’t walk a batter. The Brewers strike out 24.5% of the time, ninth most in the league. They also struck out the most in 2017. Smith is best used against teams that strike out at above average rates, and in scenarios where owners are willing to take on risk. He would probably be best served to polish his changeup into a legitimate third pitch. Until that happens Smith is a like a dice that only comes up one or six. Sometimes we’re willing to roll that dice, other times we’re best off abstaining.

Verdict:

Smith is an extreme version of the high strikeout, high risk pitcher. He’s someone that’s value depends greatly on matchup, format, and short-term context. He is a two-pitch pitcher with one effective pitch. His long term future may be in the bullpen, but as long as Smith is in the rotation he’s a matchup play.

Trevor Williams, Pittsburgh Pirates

2017 Stats: 150.1 IP, 4.07 ERA, 4.03 FIP, 2.25 K/BB

04/22 @ PHI: 6 IP, 1 H, 2 ER, 5 BB, 7 K

Trevor Williams has had a surprising start to the season with a 2.15 ERA through his first five starts. He pulled out his best performance, at least in terms of strikeouts, Sunday against the Phillies. Williams is primarily a fastball pitcher, throwing either his four-seamer or his sinker 71.4% of the time. His secondary arsenal features a changeup and a slider, though Williams does not use either of these pitches more than 20% of the time.

Despite a 2.15 ERA on the season, the peripherals don’t paint a pretty picture for Williams. His 1.40 K/BB rate is especially concerning. This start against Philadelphia was also the second time he’s walk five batters in a start, and he’s only given up a combined one hit and two earned runs in those starts. He also only has a 39.2% groundball rate despite being sinkerballer. His ability to get grounders was his best attribute as a prospect, and he’s not getting many groundballs at the major league level. So, what exactly has catalyzed his success? A .228 BABIP, 82.8% strand rate, and 3.3% HR/FB ratio. It’s as if Williams is testing the limits of how lucky a pitcher can be relative to his skills.

Williams did get eleven swinging strikes during his start against Philadelphia, but nine came on his 92 MPH four-seamer. He’d gotten eight combined in his first four starts. This probably says more about opponent strength than it does about the quality of Williams’s fastball. Even after this big swing-and-miss start Williams only has a 6.3% swinging strike rate. If there is one thing Williams can excel at it is limiting home runs. He does a good job of keeping his sinker down and PNC Park had an .860 home run factor last season, 23rd in the league. Even with that positive skill, Williams should not be trusted.

Verdict:

Trevor Williams has been extremely fortunate to have this early season success. He doesn’t have the strikeout ability (6.97 career K/9) to make up for his flaws. He’s really only worth using in NL-Only, and that’s because he is in a rotation and currently doing well. He’s tough to stream unless it’s a matchup against a bottom five offense.

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