Top Starting Pitcher Prospects - Impact Fantasy Baseball Rookies for 2023 (AL East)

The American League East is the focus of the first installment of a six-part series focused on pitching fantasy baseball prospects who are better positioned from a developmental standpoint to contribute meaningfully in 2023 MLB games.

Fundamentals will be quantified using my Fielding- and Ballpark-Independent Outcomes (FaBIO) pitcher evaluation model.

Let us begin with individual analyses of five top American League East 2023 prospects: Grayson Rodriguez, Ricky Tiedemann, Brandon Walter, Taj Bradley, and Mason Montgomery.

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Quick Overview of FaBIO

An earlier RotoBaller article more fully explains the FaBIO methodology. Every plate appearance is sorted into one of 12 event-type bins (BB+HBP, K, IFFB, Pull OFFB, Center OFFB, Oppo OFFB, Pull LD, Center LD, Oppo LD, Pull GB, Center GB, Oppo GB) and the pitcher is charged with league's average runs value for that event type.

We eventually wind up with loads of fundamentals-rooted percentile ratings expressed on a 100 to 0 scale where 97 is plus plus, 84 is plus, 50 is average, 16 is minus, and three is minus minus.

The all-in-one Overall Rating (based on expected run avoidance per batter faced over all of that pitcher's batters faced) will be used primarily as filtering criteria with relatively more attention paid to how the three core sub-Ratings of Control (or CTL, based on BB+HBP per batters faced), Strikeout (or K, based on K per batters faced), and Batted Ball Profile (based on expected run avoidance per batted ball) combine to produce Overall Rating.

Batted ball profile subcomponents like GB Rating (based on GB per batted ball), IFFB Rating, LD Avoid Rating, OFFB Avoid Rating, and Pull OFFB Avoid Rating (pull-third OFFB per batted ball) also provide useful clues as to approach, movement, and effective velocity biases.

Grayson Rodriguez, Baltimore Orioles

2018 11th overall pick Grayson Rodriguez was one percentile point shy of a plus Overall Rating in the aftermath of that draft in the rookie Gulf Coast League but has rated plus plus to better in every other pro season. Since MiLB resumed in 2021 Rodriguez has been a triple plus strikeouts starter with not quite half-plus control.

Batted ball profile has been a mixed bag over that interval. While the IFFB and LD Avoid stars have not aligned so favorably (both seasonal Batted Ball Profile Ratings are in the half-minus to average range), he has managed to avoid hits (AVG) on Batted Balls at a plus level and likely due to a favorable mix of physicality and extension.

Extreme success at strikeouts and Opposite-Handed Batters outcomes are tops among what sets Rodriguez up to be a future MLB front-half-of-rotation starter. If he can tweak the fastball arsenal to better avoid line drives while also collecting a reasonable volume of infield flyballs, an MLB SP1 outcome becomes more achievable.

Rodriguez was hit around at times in MLB spring games over 71 batters faced but landed K decently around that. If the Orioles aim to cap his batters faced circa 550 for what remains of 2023, expect the April to May MiLB SP workload to be limited some (e.g., shorter starts spaced farther apart) as they target an optimal debut date that would keep him available for multi-inning use in a potential September playoff spot push.

Ricky Tiedemann, Toronto Blue Jays

The Blue Jays took junior college true freshman lefthander Ricky Tiedemann in the third round of the 2021 MLB Draft. On the eve of the 2022 minor league season, Tiedemann remained a mystery to analysts between the relative unavailability of play-by-play event descriptions (that FaBIO, for one, relies on) at the junior college level and zero appearances in official MiLB games after signing.

His ascension through the 2022 minor leagues from A to AA was rivaled in success by perhaps only one other teenager. Tiedemann would finish that first full pro season as a plus plus to triple plus strikeouts starter with a half plus batted ball profile and half minus control.

The lagging area of Same-Handed Batter outcomes (not nearly as important for a LHSP as Oppo-Handed Batter ones) gradually improved as K versus LHB did, probably a sign that he has yet to fully develop or effectively deploy a sweeping breaker.

Only one season of FaBIO fundamentals makes it premature to carve any batted ball profile analysis in stone. Maintaining a half-plus batted ball profile that leans groundballs with better line drive avoidance makes future control deficits easier to work around.

If the batted ball profile fundamentals seen in 2022 prove as no fluke in early 2023 MiLB play Tiedemann is a viable front-half-of-MLB-rotation candidate and probably the top lefthanded starting pitcher prospect in baseball, or at least so if 2022 draftees are excluded.

Expect the Blue Jays to slow play Tiedemann, whose 2023 MLB spring usage was dialed back after mid-March shoulder soreness, in April through May with perhaps one AA to AAA mini-start per week as they try to keep him available for multi-inning MLB work in September and, optimistically, October postseason play.

Brandon Walter, Boston Red Sox

The Red Sox drafted University of Delaware lefthander Brandon Walter in 2019 in a round that no longer exists. Among what had lowered his draft stock was a true junior season of 2018 lost to Tommy John surgery.

Walter rated well in the 2019 Gulf Coast League but was surely over-experienced for a level of competition thin then in products of 4-year colleges. Since the return of MiLB Walter has been a FaBIO triple threat with almost exclusively green ratings across the board (IFFB Ratings are logically low given the plus plus GB Ratings). Walter was on track for a later 2022 MLB debut before neck/back issues ended his season in early June.

Newly Rule-5-eligible Walter was prophylactically added to the 40-man roster in the offseason and made a few multi-inning spring appearances before being optioned to the AAA affiliate for the start of 2023. Non-batted-ball outcomes stand to stay strong in AAA while some room remains to inch IFFB and LD Avoid upward via diversification of the hard arsenal and how those offerings are located. Whether the disc issues are fully resolved is the larger mystery. It would not be too bold to lightly pencil Walter in as a favorite to be the top rookie lefthanded starter in the 2023 American League.

Taj Bradley, Tampa Bay Rays

Taj Bradley was one of the youngest high school players signed from the 2018 draft class and hardly seemed ready for professional baseball per FaBIO fundamentals he flashed over 116 batters that Gulf Coast League season. Yet in 2019 he would nearly rate plus Overall as all fundamentals shot upward after a justifiably conservative assignment to the advanced rookie affiliate then.

After nearly rating plus at all of Control, K, and Batted Ball Profile in a 2021 split between A and A+ levels Bradley completed that trifecta over 285 AA batters to begin 2022. But the all-important K and Batted Ball Profile (an unfavorable turn for the OFFB is spotted in this realm) out-generation fundamentals soon sank sharply while transitioning to AAA and stayed low over a 263-batter sample at the level.

Before those AAA struggles, Bradley had a reasonable shot at a half-plus Control, half plus Strikeouts (has yet to overwhelm at K Rating), and perhaps plus Batted Ball Profile (phenomenal A, A+, and AA batted ball fundamentals and real-world outcomes) MLB SP2 future. Just where the out-generation fundamentals stand now is tough to guess without fresh AAA data to analyze. At the least one could project Bradley as a higher-floored back-of-rotation inning-eater strikethrower variety of MLB SP candidate.

Mason Montgomery, Tampa Bay Rays

Batted ball profile was a clear weak area of southpaw Mason Montgomery in 2021 both before and after the draft, with mostly red else lesser black marks in Path to Batted Ball Profile columns. Line drive avoidance of the K standout stayed problematic in 2022 A+ play even as GB Rating topped average. It would improve to just above average in AA, though that profile gain was rather offset by K sinking to 47 at the stop.

Montgomery must prove as a 2023 MiLB LHSP that he can get strikeouts in bunches while posting a batted ball profile that skews solid to better. 2023 may be one year too soon for a longer MLB SP trial but he could be very much in play for a late-season audition as a potential postseason strikeout specialist reliever.

Other 2023 AL East Pitcher Prospects on the Horizon

Sticking with the Rays... Cooper Criswell rated well at Control and Batted Ball Profile after being waiver-claimed and immediately outrighted to AAA; the off-the-40-man AAA RHSP stands to be a swingman who provides length to the MLB staff.

Rule 5 draftee (via Cleveland) Kevin Kelly has made the Rays Opening Day roster and righthanded batters set up to be his best route to outs via a mix of strikeouts and groundballs. K+IFFB control artist RHRP Trevor Brigden likely garners an MLB trial but must avoid line drives plus pulled outfield fly balls decently enough then to stick on the 40-man roster. RHRP Evan Reifert skewed "K or bust" in 2022 regular season before dominating the Arizona Fall League (82 Ctl/100 K/98 Batted Ball Profile) and still had the magic over six 2023 MLB spring training games (42 Ctl/100 K/83 Batted Ball Profile). 

Roughly two standard deviation improvements versus 2021 at each of K and Batted Ball Profile got LHRP Jose Lopez a Rule 5 looksee by the Padres this spring. LHSP Ian Seymour had Tommy John surgery in June but the upcoming offseason Rule 5 eligible could get an end-of-season K+IFFB LRHP audition. Jeff Belge, who was acquired from the Dodgers for J.P. Feyereisen, gets tried as a MLB LHRP if the MiLB fundamentals stay up.

Red Sox should try to keep wilder K+GB RHSP Bryan Mata in MLB in a long man role for all but the allowable 19 days on minor league assignment to avoid burning his final option year.

Zack Kelly put up fantastic strikeout and batted ball profile fundamentals in the last two minor league seasons but the urgency of translating more of that to MLB games rises gradually now after a lackluster 2022 debut.

Rule 5 Draft returnee (from Baltimore) Andrew Politi excited FaBIO before 2022 as a 2019 Red Sox farmhand (A+, 344 BF, 10 BF/G: 94 Overall, 24 Ctl/92 K/94 Batted Ball Profile).

This Jacob (R.) Webb checks many short RHRP boxes (he also whiffed 29 of 52 summer collegiate Northwoods League batters before the 2021 Draft) and may MLB debut during 2023 despite not being Rule 5 eligible until after 2024. 2022 FaBIO fundamentals of Taylor Broadway spiked in AA after a trade from White Sox; the probability of a RHB-leaning short RHRP future grows if batted ball profile beefens up. Ryan Fernandez must first maintain much of his 2022 K and Batted Ball Profile gains upon return to AA for a 2023 MLB trial to materialize.

Trent Palmer stuffs K and Path to Batted Ball Profile columns well and made key CTL and Opposite-Handed Batters outcomes gains versus a wilder 2021 SP campaign; chances of an MLB SP future are up versus one offseason though work remains to get there.

Blue Jays sped Yosver Zulueta through all 4 full-season affiliates during 2022 with Rule 5 eligibility looming after that season; Zulueta projects as a wilder K specialist RHRP who potentially induces weak batted ball contact at an above-average rate once limited to shorter bursts.

2021 draftee Hayden Juenger must improve K outcomes versus 2022 and post beyond plus overall outcomes against at least one batter handedness type to merit a 2023 MLB RHRP trial. Obscure Jimmies Burnette and Robbins could emerge as LHB-leaning K specialist MLB LHRP options by the season's end.

Two-option-yeared DL Hall should be a AAA starter from April to May but is trending in the direction of an MLB reliever between the most recent MiLB SP Path to Batted Ball Profile and the two most recent MiLB SP Control Ratings. Offseason 40-man rostering has Drew Rom trialed as an MLB back-of-rotation LHSP before the more OFFB+ISO-vulnerable Cade Povich is.

In both pro seasons K standout Chayce McDermott allowed far too many extra bases (ISO) on Batted Balls for a pitcher who induced an average amount of flyballs and was seldom pulled on them. 2019 junior college undrafted free agent signee Noah Denoyer should at least partially replicate his outstanding 2022 MiLB fundamentals at a larger BF/G to project more viably as an MLB SP option.

Spring starting pitcher injuries have GB+CTL RHSP Jhony Brito opening 2023 in the Yankees rotation with wilder GB+K LHSP Matt Krook on standby as a long man and likely occasional spot starter. Randy Vasquez, who joined that duo as a November 40-man roster addition, has been optioned to AAA and ideally reclaims the half standard deviations or so he lost in Control, K, and Batted Ball Profile during 2022 (versus 2021).

A sharper finish with the Yankees AA affiliate affords hope that late 2022 (Dodgers trade) acquisition Clayton Beeter can up BF/G and opposite-handed batter outcomes enough in 2023 to better resemble a long-term MLB SP candidate.

Luis Gil is firmly a K specialist short RP prospect now with just one option year remaining. Greg Weissert should still lean K first as an MLB RHRP but must avoid LD plus Pull OFFB much better ahead to limit hits (AVG) and extra bases (ISO) on batted balls roughly as well as he did in 2022 and 2021. Rule 5 returnee (via Mets) Zach Greene should eventually be tried as a middle reliever whose usage is biased toward RHB.

Carson Coleman was an entirely different FaBIO animal in 2022 than in 2021 and now must sustain enough of those far more robust pitching fundamentals to state a candidacy for a 2023 MLB RHRP trial. Fellow RHRP Aaron McGarity was last spotted before 2022 in the 2019 Arizona Fall League with a 42-batter 86 CTL/92 K/88 Batted Ball Profile line that followed a leaner 239-batter 79 CTL/67 K/37 Batted Ball Profile one compiled over 3 levels of A baseball.

Impact AL East Pitcher Prospects Farther Down the Pipeline

Fantasy league players with an eye cast to MLB seasons beyond 2023 should follow Rays RHP Cole Wilcox (another Tommy John returnee who is perhaps already a Top 20 MLB SP prospect), Orioles RHP Carter Baumler (shoulder trouble swiftly ended a remarkably robust 2022 return from Tommy John surgery), Yankees RHP Drew Thorpe (possibly 2023 Tommy John returnee RHP Brendan Beck, too), Red Sox RHP Luis Perales, and Blue Jays LHP Cooper Benson (possibly 2022 prep first-rounder LHP Brandon Barriera contingent on how the early fundamentals from his pro debut sort out).

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