Fantasy Baseball League Winners: Unlikely Aces Worth A Roster Spot?

Tommy Bell's weekly deep dive into three fantasy baseball starting pitchers to decide if their surprisingly good form merits a roster spot or staying on the waiver wire.

Mid-June means warmer nights, more humidity, and some pitcher blow-ups that will balloon the ERA of many fantasy managers. More than ever, it's important to nail some pitcher pickups on the waiver wire. A timely add now could pay huge dividends as we quickly approach the halfway point of the MLB season.

Each week, I'll take a look at three starters who have found recent success despite lesser outlooks across the fantasy landscape. By diving into some analytics, we can try to predict whether a back-end arm can potentially carry fantasy managers to glory, or if the strong performances are more likely a flash in the pan.

Are these unlikely aces for real, or is it safe to leave them out on the waiver wire with negative regression surely coming in bunches quickly? Let's take a deeper look!

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Kyle Harrison, San Francisco Giants

54% Rostered

After a few blips on the radar in late May, Harrison got his game back on track with a strong start against Houston on Monday night. Since the end of April, the lefty has been a consistent source of ground balls and quality starts, racking up four in his last nine appearances.

Harrison started seven games last season, and while his strikeout rate was a touch higher than 2024, his fly-ball rate caused some home-run issues, ballooning his xFIP to 5.01. This season, the 22-year-old has dropped his fly-ball percentage to 40% while increasing his ground-ball rate tremendously, up to 42%. As a result, Harrison has allowed just nine homers in 14 starts for a HR/FB rate of 9.6%.

The biggest change in pitch selection for Harrison from 2023 to 2024 has been a 9% jump in changeup usage that correlates with a sizable drop in cutters. While it's disappointing to see his strikeout rate lessen nearly 4%, the adjustment in fly balls has allowed him to avoid crooked numbers.

Kyle Harrison, Nasty 86mph Changeup...and Sword. ⚔️ pic.twitter.com/9V5Atp2Iou

— Rob Friedman (@PitchingNinja) April 27, 2024

There's room for strikeout growth for Harrison as he continues to improve the changeup, and while he's not dominating by any means, the consistency is worth a lot these days, especially considering how many of his starts will come in the pitcher-friendly confines of Oracle Park.

The roster percentage of 54% on Yahoo! seems about right, as I would be hesitant to lean on Harrison heavily if I was lacking in the strikeout department. But in points leagues and roto leagues in which ERA could be an issue, there's plenty to like from the southpaw for the rest of the season.

Bailey Falter, Pittsburgh Pirates

16% Rostered

We may be a week late on this one, as Falter struggled mightily against the Dodgers and pitches Wednesday night (a few hours after I'm drafting this article) against a righty-heavy Cardinals lineup in St. Louis. But what the lefty has quietly accomplished thus far in 2024 since his brutal beginning still deserves mentioning.

If we remove the 27-year-old's catastrophic debut at Miami and his two-homer outing last Thursday against a Dodger lineup that was due for a big night, Falter is 3-2 with six quality starts in his 10 appearances for Pittsburgh. The former Phillies pitcher has seen his strikeout percentage dip in each of his last four years while increasing his walk rate, but somehow he's finding success for the Buccos among their group of talented young arms.

Unfortunately, it appears like more negative regression is on the way. Falter has a very low .213 BABIP despite a career-high 42.3% hard-hit rate. That results in a 4.99 xERA, which suggests his current 3.69 ERA will be on the rise sooner rather than later.

The one saving grace with Falter could be his new approach to completely lean on his fastball, throwing it more than 50% of the time. If that pitch can keep skirting the analytics to yield unlikely results, we could just see the Pirates' back-end arm surpass expectations all year. However, odds suggest that Falter will be best left on the waiver wire in most leagues barring a season full of continued GREAT luck.

Spencer Arrighetti, Houston Astros

13% Rostered

The most exciting arm on this week's list comes in the form of Arrighetti, the 2021 draft pick by the Astros who is just 11 starts into his MLB career but has plenty under the hood to be excited about.

The right-hander got off to a rocky start, allowing four runs or more in three of his first five starts and failing to reach five innings in his first three starts. However, the stuff was evident, and some bad luck presented a buy-low opportunity. Both metrics and the eye test suggested there were more strikeouts and less hits on the horizon.

Spencer Arrighetti, Wicked 79mph Breaking Ball. 🤢 pic.twitter.com/kb1WPoWX2X

— Rob Friedman (@PitchingNinja) June 11, 2024

In his last three outings, Arrighetti has gone a combined 14.2 innings with 18 strikeouts and just nine hits. The issue, however, will continue to be his high walk rate, which currently sits at 4.99 BB/9. Even still, it's hard to deny that his four-seam fastball will play at this level. He's getting more and more whiffs on his wicked curveball displayed in the embedded tweet above.

If you're desperately trying to gain ground in the WHIP category, the 24-year-old may not be for you. However, the quality of pitches should only continue to get more effective as he improves command, and the walks can only go one way from here. If Arrighetti starts to go six innings consistently while allowing about two walks per outing, he'll be a must-start pitcher in most matchups as long as the Astros let him go.

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