Are You For Real? Surprising SP Starts from Week 8

May 26, 2021

Elliott Baas looks at starting pitchers who turned in surprising starts recently. These SP could emerge as waiver wire targets and sleepers, or simply mirages.

As we approach Memorial Day, season-long numbers are starting to feel a lot more real. That makes it even more important to analyze surprising starts from pitchers who may not have been caught up in the whirlwind of April breakouts. This week we're taking a trip across the junior circuit, looking at a pitcher from the AL East, AL Central, and AL West. Sorry NL-only players, but the American League happened to produce some of the most intriguing outings of the past week.

Casey Mize put up his fifth straight quality start for Detroit this past week, while Jordan Montgomery fanned 11 in a magnificent performance on Friday. Some guy named James Kaprielian put up his second solid outing in Oakland and thrust his name onto the fantasy radar despite being relatively unknown just two weeks ago.

Roster percentages quoted in this piece are based on Yahoo availability and are accurate as of 05/24/2021.

James Kaprielian, Oakland Athletics

14% Rostered

2020 Stats: 3.2 IP, 7.36 ERA, 9.74 FIP, 2.0 K/BB ratio

05/21 @ LAA: 5.2 IP, 4 H, 2 ER, 1 BB, 9 K

Kaprielian is not a well-known name to even the most obsessive baseball fans (I had to check the spelling of his name multiple times while writing this section), but the 27-year-old righty has been impressive in his first two big league starts. Kaprielian has posted a 2.53 ERA in 10.2 innings thus far, and with a monster 12.66 K/9 ratio. Fantasy managers are rightfully intrigued by the Athletics’ newest starter, but who is James Kaprielian, and can he really be an out-of-nowhere contributor in 2021?

I said Kaprielian wasn’t a well-known name, and that was true coming into 2021, but Kaprielian was a notable pitching prospect out of UCLA back in 2015. He was a first-round pick by the Yankees in 2015, and made it as high as the 43^rd best prospect in 2017 for Eric Logenhagen of FanGraphs. He was one of the pieces dealt back to Oakland in the Sonny Gray trade, and the only player left from that deal who could make a positive impact for the A’s. Chronic elbow issues and a 2017 Tommy John surgery severely hampered Kaprielian’s development, but as with a lot of Tommy John casualties, the remnants of talent remain with the player. Kaprielian came into the season as Oakland’s tenth-rated prospect per MLB pipeline despite being older than most minor leaguers, which speaks to how scouts think of the righty.

On the mound, Kaprielian gets it done with a five-pitch mix consisting of a four seam fastball, sinker, slider, changeup, and curveball. The sinker and curveball have been show-me pitches for Kaprielian, as he uses both of them under 7% of the time. It’s mainly been about the four-seam, slider, and changeup, which is about the standard repertoire for a starting pitcher in this era. Kaprielian’s most revered offering is his slider, an 86 MPH bender with excellent horizontal break. It has been effective for Kaprielian thus far, as opponents are hitting .100 with a 19% swinging strike rate against the pitch. He got three of his 13 whiffs with the pitch in his start against the Angels, which was good for a 60% whiff rate since Kaprielian only threw 19 sliders in that start.

Kaprielian’s slider usage seems a little low considering how good the pitch can be. The average big league starter throws a slider 17.8% of the time (including pitchers who may not throw a slider) and many pitchers are throwing sliders 25% of the time or more to great success. Though he’s been good so far, Kaprielian might find it fruitful to use the slider more often as he builds up towards a bigger workload. He may also avoid overusing the slider to try and preserve his elbow given his long history of arm troubles.

Kaprielian was also known for his mid-90s fastball velocity, but he hasn’t shown that as a starter yet. He averages 93.5 MPH with his four-seamer, topping out around 95 MPH. Not only is the velocity middling, but his 2135 RPM spin rate is also unimpressive. There is one thing exceptional about Kaprielian’s fastball, which is its 36-degree average launch angle against. That has helped Kaprielian keep the batting average against his heater at .238, with an xBA of .170.

Much has been said and written about the benefits of elevating the ball for power, but the fact remains that flyballs are the least likely batted ball type to become a hit. If a flyball isn’t over the fence or in a really favorable spot, it’s going to be caught. Fly ball pitchers do have the benefit of maintaining lower BABIPs than ground ball pitchers. Kaprielian has experienced that benefit so far, with a .250 BABIP against and a microscopic 19.2% ground ball rate.

One concern with this pitching style is home runs, and Kaprielian has been bit by the longball thus far, having served up two home runs against the Angels. Kaprielian also has an average exit velocity against of a scorching 91.8 MPH, including a 92.4 MPH average exit velocity against his fastball. The fly balls he gives up aren’t all lazy popups either, as Kaprielian has the tenth-highest average flyball distance (min. 25 BBE) at 217 feet. This is diving deep into the grains of a pitcher who’s only made two starts, but it’s a pitching style that is conducive to power allowed. He’s fortunate to pitch in the spacious Oakland Coliseum for half his games, and pitches in pretty good division for pitcher-friendly ballparks, with only Minute Maid Park and Angels Stadium grading above average for power.

Verdict:

It’s hard to recommend Kaprielian in standard or shallower leagues simply because we haven’t seen very much from him, and there isn’t much minor league data either because he’s spent so much time on the shelf. In deeper leagues, you need to pounce early on anyone who shows promise, and Kaprielian has shown enough that he should be added in AL-only leagues and 15-team leagues or deeper. Long term, Kaprelian will need to outpitch Cole Irvin to keep his spot in the rotation, something that is certainly possible given Irvin’s prior history and recent blowup start. Kaprielian should not be used in tough matchups quite yet, but he does draw the Seattle Mariners at home next time out and if he stays in the rotation he'd have a two-start week at Seattle (yay!) and at Colorado (oh no!). If he can continue pitching well he might earn a start in the two-start week, even with one of them coming in Coors Field.

Jordan Montgomery, New York Yankees

40% Rostered

2021 Stats (prior to this start): 41.2 IP, 4.75 ERA, 3.99 FIP, 3.7 K/BB ratiamao

05/21 vs. CWS: 7 IP, 4 H, 0 ER, 0 BB, 11 K

Montgomery came out firing on Friday, putting up perhaps the best start of his career as he carved up the White Sox for a career-high 11 strikeouts. He wasn’t rewarded with a win thanks to an equally good performance on the other side from Carlos Rodon, but this was still a day to remember for Montgomery. Montgomery has flirted with a breakout for parts of four seasons prior to 2021, but has never been able to sustain long term success. With a career-best 3.42 FIP through his first nine starts, Montgomery could finally be taking the next step in the Bronx and become a viable fantasy starter.

While many players on the Yankees often find themselves in the middle of the media spotlight, Montgomery has somehow flown under the radar despite spending six seasons in New York. It’s easy for Montgomery to remain unnoticed because he hasn’t exactly lit up the box score and his repertoire isn’t eye-popping. Montgomery has a five-pitch arsenal consisting of a four-seam fastball, sinker, cutter, curveball, and changeup. His fastball has averaged 92.7 MPH this season, which is the highest of his career, and Montgomery’s been averaging over 93 MPH with his fastball over his last two starts. His most commonly used secondary pitch is his curve ball, an 80 MPH offering that’s been his most effective pitch this season.

Effective is an understatement when it comes to Montgomery’s curve ball, as opponents have flailed at pitch for a .136 AVG and a 21% swinging strike rate. These results are mostly earned too, as Montgomery has a .146 xBA and .218 xSLG with his curve ball. This success can be partially attributed to the 56.5% ground ball rate Montgomery has maintained with his curve ball, which is over 10% higher than his career mark. Montgomery has done a much better job of commanding the curve ball and keeping it down in and below the zone this season. Below is a heatmap comparison of Montgomery’s curve ball usage from previous seasons (top) to 2021 (bottom).

The ball is kept down from all hitters and down and away from left-handed batters. Montgomery’s curve ball has always been his most effective pitch, but he has taken it to another level this season. The pitch was especially dominant in this effort, generating eight of his 17 whiffs for a 57% whiff rate. After using the pitch under 20% of the time through his first three starts, Montgomery has ramped up his curve ball usage to 28.6% of the time over the last month. That increased curve ball usage has coincided with positive results, as Montgomery has a 3.98 ERA, 2.49 FIP, and 9.7 K/9 over his last six starts.

The curve ball has been the main driver of his hot streak, but it’s not the only pitch that’s been kind to Montgomery this season. Batters are hitting .200 with a 19.9% swinging strike rate against the changeup this season. This isn’t abnormal for Montgomery either, as his changeup has a 17.6% swinging strike rate for his career. Montgomery has begun throwing his changeup more often over the last two seasons, and is using it 24% of the time in 2021. He’s been a bit fortunate on the results-end with this pitch as he has a .282 xBA and .580 xSLG against. However, Montgomery has never had such high expected or actual stats with the changeup in the past, so we shouldn’t be too worried about these numbers yet. Increased changeup usage should be a good thing for Montgomery as it’s one of his better offerings and would lead to a higher strikeout rate if he maintained this type of usage over the course of the season.

An increase in changeup usage and the introduction of a cutter has meant Montgomery has thrown his fastballs (both the four-seamer and sinker) 35.2% of the time, a career-low. This should work out favorably for Montgomery, as batters have an .816 OPS against his four-seamer and a .932 OPS against his sinker all time. The Yankees have famously coached their pitchers to de-emphasize their fastballs in favor of more effective secondary pitches, and Montgomery could be heading down that path as well.

Verdict:

With two solid offspeed pitches Montgomery has the potential to maintain a sub-4 ERA and an above average strikeout rate. His success this season was preceded by changes he made in 2020, where Montgomery posted a 3.87 FIP and 3.65 xFIP, but bad luck left him with a 5.11 ERA that disguised his progress. Montgomery does have a fortunate .280 BABIP, but even if that regresses to league average, he should remain a good option in neutral and positive matchups. His next three starts are against tough AL East matchups at home, facing Toronto this week and then drawing a two-start week against Tampa Bay and Boston. Such is life for an AL East hurler, but I'd still use him in the two-start week. Tampa Bay's 27% strikeout rate as a team makes it easier to roll pitchers out against them, even though they have 107 wRC+ as a team (as of writing this).

Casey Mize, Detroit Tigers

44% Rostered

2021 Stats (prior to this start): 46.1 IP, 3.69 ERA, 4.92 FIP, 1.8 K/BB ratio

05/23 @ KC: 6.1 IP, 3 H, 1 ER, 1 BB, 6 K

After a disastrous start to the season that had many questioning whether the top pitching prospect would pan out in 2021, Mize has quietly strung together five straight quality starts. His most recent start against the Royals on Sunday was the best of the streak as Mize allowed only four baserunners and had an 8.53 K/9, though he wasn’t awarded with a win thanks to a walk-off home run surrendered by Michael Fulmer. Even so, Mize has a 2.25 ERA during his five-start stretch. With all the hype that’s surrounded Mize over the past few years, it’s easy to see why fantasy managers would get excited for a potential breakout, but is it too soon for the Tigers prodigy?

Even a cursory look at Mize’s profile can make one see why he’s garnered so much hype as a prospect. He’s a pitcher that has everything scouts drool over. At 6’3” and 220 pounds, he’s got the ideal starter’s build. Mize dominated at a D1 baseball school (Auburn), and he throws a mid-90s fastball along with two excellent secondary pitches in his slider and splitter. The only thing slowing him down was a teensy bit of shoulder pain, but Detroit wrapped their young star in bubble wrap after a 2019 injury scare and Mize hasn’t dealt with shoulder issues since. Although he hasn’t dealt with shoulder issues, he’s certainly dealt with performance issues over his young career. Prior to his quality start streak, Mize had a career 6.24 ERA, 6.44 FIP, and 2.2 HR in 11 starts. Luckily for him, Detroit has zero chance of competing for anything other than the number one overall pick, so Mize could easily be left in the rotation to work through his troubles.

Work through those troubles Mize has, and the most notable change comes in the form of his slider. Mize went from throwing a hard but low movement cutter in 2020 to a more traditional slider in 2021, picking up about three inches of movement with the pitch this year. Here is a comparison of his slider/cutter from 2020 (top) to the reworked pitch in 2021 (bottom)

The pitch has better movement away from right-handed batters, which is something we can see reflected in a heatmap comparison of the pitch from 2020 (top) and 2021 (bottom) as well.

This isn’t just change for the sake of change either, as the improvements have shown up in the results for Mize. Batters are hitting .174 with a .540 OPS against his slider this season, which are both marked improvements from 2020. It’s nice to see Mize make such a change at an early stage in his career because it shows he and the folks surrounding his development recognized a potential flaw and were able to rectify it over the course of an offseason. Mize has the type of raw ability to make these types changes, which should help him be an adaptive pitcher over the course of his MLB career.

While this change is a step in the right direction for Mize, I still question his ability to generate strikeouts at an above average rate. Even with the adjustments to his slider, the pitch has just a 12.6% swinging strike rate, a paltry mark in today’s game. Even more disappointing is how poorly his splitter has performed during his short career. The pitch has been getting hyped since Mize’s college days, but batters have had no problem against the offering with a .288 AVG and a meager 10.7% swinging strike rate. At times the pitch has looked downright nasty, but Mize has had inconsistent command of his splitter during his short career. This is likely the next issue for him to tackle, but don’t count on it getting resolved in the middle of the season.

It also cannot be overlooked how fortunate Mize has been this season, with a .232 BABIP against and a 79.5% strand rate. He’s also tied with Patrick Corbin for the sixth-worst K/BB ratio among qualified starters at 2.0, sharing company with the likes of Carlos Martinez and Jose Urena at the bottom of the leaderboards. Even during his hot stretch, Mize has been riding a .188 BABIP and 4.3% HR/FB ratio, two marks that are wholly unsustainable over an extended period of time. Progress has been made, but the breakout isn’t here yet for Mize. In redraft leagues he might have moderate trade value given the hype surrounding his name, and a manger who takes a surface level view at Mize’s recent performance may believe he’s breaking out when he’s actually riding some good fortune.

Verdict:

Mize has made progress with his slider this season, but he's still a developing player and does not yet deserve the trust of fantasy players. His splitter is still underperforming and his fastball velocity has oscillated between 93-95 MPH this season, which is the difference between average and above average. His .232 BABIP and 79.5% strand rate will eventually normalize, and when that happens, Mize's ERA will likely climb to the 4.25-4.75 range. He doesn't produce enough strikeouts or get enough chances for wins to make him worth the trouble in redraft leagues. He is a sell in non-keeper or dynasty formats. His long-term outlook is still positive and it will be exciting to see what the future holds for Casey Mize.

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