Analytically Speaking: 5 Starters Who Should Be Better Than Their 2020 Seasons

Baseball is a game of numbers. We judge players, teams and eras rightly or wrongly against their peers using an ever increasing and sophisticated numbers system that the game has always been able to provide but that our imaginations and technology have only began to be able to realize. There has never been a time in baseball history where more information has been available to the regular fan than now. It can be absolutely awe-inspiring.

Earl Weaver never had Statcast, which is a mini tragedy in itself. Today, between the numbers of Fangraphs and the primary-sourced data of Baseball Savant the real inside story of the players and teams of this game we love can be discovered if you look hard enough. Its all readily available for you and me.

That is what we are here for today, the real inside story. Below we have a full starting rotation of five different pitchers whose basic statistics in 2020 would suggest that this past season was a real letdown, and that perhaps they have already or never will reach their peaks. Digging one step deeper though, we can use analytics and some of the basic principles surrounding them to suggest something different. Perhaps 2020 wasn’t as bad as the runs that came across the board may seem. With that in mind, there is reason to feel secure that better times are ahead for these five individuals in 2021.

We list them from the lowest to highest degree of confidence, starting with…

5. Kyle Gibson, Texas Rangers

2020 Basic Statline: 2-6 67.1 IP 5.35 ERA 1.53 WHIP

The 2020 season was Gibson’s first in a 3-year free agent deal worth $28 million for the Rangers as Texas had hoped to make him part of a strong pitching attack that included former All-Stars Lance Lynn, Mike Minor and Corey Kluber. However, after a trade of Lynn this off-season, poor performance from Minor in 2020 and a nearly all-season encompassing injury for Kluber, Gibson is actually the only man remaining standing among the four in Texas in 2021.

While he may have weathered the storm better than the three headed monster that Texas tried to put together, his 2020 was similarly unfortunate. His 5.35 ERA was the highest of his career while he allowed the second most hits of any Major League pitcher.

So why the reason for optimism? While Gibson may have allowed a lot of hits at least some of those hits, particularly the ones that went over the outfield fence, may be been a matter of bad luck. Gibson’s Home Run to Fly Ball (HR/FB) ratio in 2020 was 26.7%. That’s right. More than 1 out of every 4 flyballs Gibson allowed last season were round trippers. That percentage was not only 5 points worse than anyone else in the league that qualified, but 12 points higher than his career average, which is right in line with the Major League baseline of 14.8% for 2020.

Which lends the question, what gives? Did Gibson have some crazy statistical outlier of a season or was some other factor in play?

One thing we can rule out is Park Factor. Globe Life Field, the Rangers newly built 2020 home, ranked dead last in Home Run Factor in 2020 (lower rank means less homer friendly) while Target Field, Gibson’s home for the 2019 season ranked 24th. Target Field was also Gibson’s home in 2014,the stingiest season of his career in terms of giving up the long ball. Contrary to expectations, the ballpark actually ranked 14th in Home Run Factor that season. Gibson’s crazy home run-allowing season doesn’t appear to be a product of his environment.

Nor was Gibson prone to giving up a particularly high rate of hard contact in 2020. Statcast measures Barrel%, which is the percentage of the times a hitter not only hits the ball with a high exit velocity, but also at the angle which is most efficient to do offensive damage. Gibson’s Barrel% in 2020 was 7.2%, which was below the median percentage for pitchers who faced at least 150 batters in the 2019 or 2020 seasons. Most pitchers had a worse Barrel% than him, so those home runs also weren’t the product of an excess of hard hits.

Which leads us to the avenue of statistical noise. At the very least Gibson must be an outlier. The average home run in Major League Baseball produces 1.6 runs. Gibson was allowing 1.6 runs at a time faster than anyone in the league for reasons that don’t have obvious explanation. With that being the case, I would expect this phenomenon to cease in 2021.

Gibson’s never been a top of the rotation ace, but he’s certainly better than his 5.35 ERA in 2020 suggests. I think its fair to expect him to at least be a serviceable innings eater for a Rangers rotation searching for some direction in 2021. Unfortunately, he may find himself at the top of a rotation that only has Dane Dunning and Jordan Lyles as possible candidates to challenge him as the number 1 guy. Its probably not much consolation, but Rangers fans can expect him to at least be better than 2020.

4. Sean Manaea, Oakland Athletics

2020 Basic Statline: 4-3 54.0 IP 4.50 ERA 1.20 WHIP

Manaea has been a top-level innings eater for the Athletics when healthy, which has pretty much never been the case for a full MLB season before 2020. The first lefty on our list responded to his first full season this past year by providing the worst ERA of his career. The 28-year-old allowed 57 hits for the season, poor enough to place him in the top 15 worst pitchers in baseball. Still, certain more sophisticated metrics were kind to him.

For one, you can measure pitcher success in total through three combined stats. The first is the Barrel% that we described regarding Gibson. The other two are K% and BB%. By looking at these three numbers you can get a picture of a pitcher’s ability to limit the type of hard contact most likely to lead to hits, limit free passes on the bases and maximize making outs by taking matters into their own hands. Arguably, the rest of the game from a pitcher’s perspective can be considered as boiling down to statistical noise. Good luck and bad luck have a lot to do with the remaining balls put in play. This line of thought isn’t fool proof, but it’s among the best measures we have. Similar processes are the inspiration for stats like FIP.

So despite his number of base hits allowed, Manaea met the criteria of being better than the median in Barrel% (7.1% vs 7.3% median) and BB% (3.6%, in the Top 3 percent of the league), though he was below the half-way mark on strikeout rate. However, what those statistics don’t immediately bring to light is that Manaea pitched the entirety of the 2020 regular season against the West divisions.

Five of the six best teams in terms of not striking out were in the AL or NL West. So were six of the top ten. Manaea came back from shoulder surgery in 2019 and recorded a career high strikeout percentage of 27.5%. There was likely some small sample size hijinks going on there, but I would still expect Manaea to punchout batters at a better rate than the 20.3% (23.3% is median) that he did in 2020 while facing some of the hardest teams to put away in baseball.

Manaea is also another victim of some bad baseball luck. Manaea’s Batting Average on Balls In Play (BABIP) for the 2020 season was .311 (.292 was average). We know this is not the product of a ton of hard contact considering Manaea’s barrel rate, and when you consider that the defense around Manaea averaged a BABIP of .285 regardless of the pitcher on the mound, you can see its not the product of on-going bad defense that needs to be fixed either. Balls into holes, bleeders and bloopers likely did a lot of damage to Manaea’s standard statline.

Some combination of the likelihood that Manaea will get more outs without having the ball in play (also known as strikeouts) and the likelihood that he will also be more fortunate to find outs when the ball is in play should lead to better overall outcomes for him in 2021. Assuming his health continues, there is no reason to believe he wouldn’t pitch more to the level of his FIP in 2020 (3.71) or at least his career ERA of 3.85 at the very least. While the competition on a day-to-day within the division might not be as fierce as last season, the Athletics will absolutely need him in order to make another run at the AL West title. They should feel more secure than his standard numbers suggest.

3. Tyler Glasnow, Tampa Bay Rays

2020 Basic Statline: 5-1 57.1 IP 4.08 ERA 1.13 WHIP

Those with short memories will remember Glasnow from a Rays World Series run where he saw gradually increasing ERAs from round to round in the playoffs. He suffered two losing decisions at the hands of the Los Angeles Dodgers on their way to the title. While Glasnow’s regular season was at least better than his October, bookended success in 2019 with a long layoff on the IL in between was the best he has ever looked.

Glasnow suffered no trips to the IL in 2020, which was a season known as hard on pitchers’ health. Having surpassed that milestone, there is reason to believe that Glasnow couldn’t be both healthy and more effective in 2021. Firstly, since receiving a clean bill of health in September of 2019, Glasnow is pitching in the high 90s on his already highly effective fastball more consistently.

Harkening back to the metrics of Barrel%, K% and BB%, if you add Barrel% and BB% together and then subtract K% from them, you get a neat, little back of the napkin stat for pitcher effectiveness. Proving the general accuracy of this quick calculation you will find that 19 of the Top 20 pitchers in “Barrel+BB-K” in 2020 had an ERA under four. The only pitcher not to have that distinction was Glasnow.

Michael Simione from Fangraphs would argue that Glasnow’s inflated runs allowed were a product of leaving too many pitches over the middle of the plate, however I’m not sure how effectual that really was.

Admittedly, Glasnow could do more to not live in the middle of the plate. He tied for 73rd best out of the 100 pitchers who pitched 44 innings in 2020 in meatball% (its exactly what it sounds like). That’s not very good, but here are some of the names at the same or a worse rate on that list: Gerrit Cole (73rd, 2.84 ERA), Taijuan Walker (77th, 2.70 ERA), and Clayton Kershaw (dead last!, 2.16 ERA).

I’m not so sure it was the balls in the middle of the plate that did him in. Further, Glasnow’s Barrel% was a little high at 7.7% (just above the median of 7.3%), but mostly he suffered the same fate as Gibson. His HR/FB rate was 23.4%, a full and unsustainable 9 points higher than the league average while Tampa’s Tropicana Field came 23rd in Home Run Factor. Given the situation, pitchers giving up homers on a quarter of their flyballs aren’t going to continue to do so and consequently are going to begin to give up fewer runs.

Lastly, while Glasnow may live in the middle of the plate a little bit too much, he also knows how to live on the edge. Throughout his entire career, his percentage of pitches on the edges of the strike zone have been above the average (42.6% for his career vs the 39.3% league average). We can then surmise that he absolutely pounds the strike zone, and he does it with a fastball that has new life since he’s become healthy and a curveball that’s drop ranks in the top 13% of the league in both of the last two seasons. His stuff is just too good for him to keep struggling, particularly when he is around the plate so much. There’s absolutely a lot to like about Glasnow in 2021 as the Rays will be more dependent on him to be on top of his game after the trade of former Cy Young Award Winner Blake Snell.

2. Luis Castillo, Cincinnati Reds

2020 Basic Statline: 4-6 70.0 IP 3.21 ERA 1.23 WHIP

If Gibson is the pitcher on our list that had the worst 2020, then Castillo is easily the entry that had the best season. In his third full season in the Majors, he posted the best ERA of his short career while being part of a pitching staff that helped propel Cincinnati to the playoffs.

Castillo enters his first year of arbitration in 2021 and will do so not just with an increased paycheck, but increased responsibility. At this time, it seems that 2020 NL Cy Young Award winner Trevor Bauer will not be returning to Cincinnati’s rotation, opening the need for either Castillo (if they hold onto him) or Sonny Gray to step up as the team’s ace in what is likely a low ceiling but deep NL Central division.

Castillo may very well be poised to make another leap in 2021 though. 13 starting pitchers in 2020 rated above average in Barrel%, K% and BB%. Castillo was among that thirteen. His Barrel% was a miniscule 4.5% (7.3% is average) which was good for 10th amongst pitchers with at least 44 IP.

Conversely, his BABIP was .329. That was tied for 11th WORST among pitchers with 44 IP. In short, Castillo did his part. He limited the type of hard contact that is most guaranteed to lead to base hits and home runs, and for his efforts he was not rewarded whatsoever. For that reason and for the fact that the only season in which Castillo’s Barrel% was higher than the median was his first full year in the Majors, we can only surmise that some of the hits Castillo allowed were bad circumstance. Expect those circumstances to change and for the number of baserunners and scoring opportunities against the Cincinnati right-hander to lessen.

Still, not only was Castillo’s 2020 performed at a high level despite some bad fielding luck; it was also performed despite the worst mastery of his changeup that he has had in his short Major League career. Castillo throws his changeup more than any other pitch in his arsenal. He threw it 31.6% of the time in 2019 when it accumulated the fifth most Run Value (-26, negatives are good) of any pitch in baseball according to Statcast. It has been far and away the best pitch he has, except for in 2020 when it only accumulated -2 Run Value, making it a middle of the pack performing pitch. History, however short it may be, would suggest that Castillo is going to turn his changeup back into a dominant weapon like it was from 2017-2019. I would not expect a repeat performance of 2020, but rather an even improved attack including a return to normalcy for his changeup.

1. Jordan Montgomery, New York Yankees

2020 Basic Statline: 2-3 44.0 IP 5.11 ERA 1.30 WHIP

Montgomery is the absolute poster boy for all of the statistical inconsistencies that we have talked about over the last four pitchers. As a back-half of the rotation starter for the Yankees in 2020, at a single glance his ERA of 5.11 might not seem all that outrageous. Include the fact he barely pitched in the Majors in 2019 due to injury and at just over 28 years old he has the appearances of a lefty journeyman who might have his future in the bullpen. Conversely, with a rotation that was searching for answers in 2020 and still is deep into this off-season it appears that the Yankees might need Montgomery to step up in 2021 if New York wants to be serious about World Series plans. But perhaps fans need not worry about Montgomery.

Over the course of both 2019 and 2020 pitchers were able to be better than the median in Barrel%, K% and BB% a total of 67 times, among those entries was Montgomery’s 2020 season. The average ERA of the 67 pitchers that qualified was 3.22, nearly 2 runs lower than Montgomery. His best comparisons in terms of similar Barrel+BB-K numbers over those two seasons are 2019 Kenta Maeda (4.04 ERA) and 2019 Clayton Kershaw (3.03 ERA).

Montgomery also suffered from BABIP woes. His BABIP of .320 is not only grotesque in comparison to the league average of .292, but when you consider the fact that the Yankees as a team actually had a BABIP of .280 it looks even worse. Once again, this is not a matter of giving a bunch of rockets off the bat. Not only was Montgomery’s Barrel rate 6%, significantly better than the league median but he finished in the top 5% of the league in Exit Velocity Against (84.6 MPH). Batters simply didn’t hit the ball with much force against him in 2020 all while he was also in the top 8 percent in walk rate (4.7%).

Montgomery’s 2020 actually had the makings of a top of the rotation performance. I think the Yankees are right-minded to have him in their rotation for 2021 considering a past track record of sub-4 ERAs (outside of the 2019 season where he only threw 82 Major League pitches). A left-handed pitcher with the ability to neutralize left-handed hitters (lefties have hit .195 vs. him in his career while slugging just .331) in the lefty-friendly Yankee Stadium is a perfect fit for them.

Whether New York can or can’t add star power to their starting rotation I wouldn’t worry about Montgomery’s spot. He deserves the right to prove himself after a very disadvantageous 2020.


Usually at this point we could pose the question of what we have learned, but ultimately, that has yet to be seen. We can hope and extrapolate and surmise all we want from the 2020 season regarding these five pitchers or really any ballplayer we want, but we will have to wait until the games are played to see just how true the data really is.

In the meantime, if you’re a fan from a team of one of these guys, take the moment to feel a little bit better about their potential in 2021. Feel good about the fact that your team is likely getting good value. All five of our entrants come in as making less than $10 million in 2021 and the top four are all making below $6 million. If you have a fantasy team, give these guys some late round consideration. You’ll likely to be able to snag most if not all of them at that time.

But more than anything, enjoy the game and enjoy the numbers while we wait for winter’s cold creep to slowly comes to a close. Pitchers and catchers report in less than a month.

After all, spring brings even more hope than data does.

Twitter: @DJLJR26

Featured image from Fantrax HQ

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