2022 Review: Pitcher xERA Underperformers

Last week, I discussed the hitters who underperformed their Statcast xwOBA marks most. Given that projection system typically weigh historical results in some fashion to compute an upcoming season forecast, it’s possible that list includes some hitters who may be underprojected. So let’s now turn to the pitching side. We’ll start by reviewing the starting pitchers who recorded at least 150 innings that most underperformed their Statcast xERA mark. Note that based on my calculations, the league xERA was 4.03, versus a 3.97 actual ERA. So on average, pitchers slightly overperformed their xERA marks.

Sean Manaea was far and away the biggest xERA underperformer, posting the highest ERA of his career, despite underlying skill metrics right in line with his history. You can see from the above table that this wasn’t a BABIP thing, as he finished right at his career mark and only marginally above the .289 league average. Instead, Manaea couldn’t keep his fly balls in the park, posting a career worst HR/FB rate, despite the league HR/FB rate dropping to its lowest since 2015. Furthermore, his LOB% fell to its lowest over a full season, with only his short 2020 season campaign settling lower.

What’s worth noting is that if anything, Manaea had been a consistent xERA beater through his career, overperforming in all four of his full seasons previously. The good news is he’s moving to a home park that’s toughest in baseball to hit home runs in. For a guy who has never posted a HR/FB rate below 10.6% and is coming off the highest FB% of his career, this is a big move. He’s a nice end game buy.

I blame Lucas Giolito and my brutal patience waiting for his results to match his underlying skills for failing to finish in the money in my local league. Yes, his strikeout and walk rates moved in the wrong direction and he lost a chunk of fastball velocity. Those are real concerns moving forward. But he surely didn’t deserve a .340 BABIP, after having never posted a mark over .273 previously! That’s an absurd spike. You might be tempted to point to his high LD% and low IFFB%, which are problematic. But Statcast’s xERA formula accounts for each batted ball. Clearly it’s accounted for considering this is by far the highest xERA Giolito has posted since he became good back in 2019. With a loss of velocity and drops in both SwStk% and strikeout rate, he’s no longer the top tier pitcher he has been. But hey, he’s still young enough that his velocity could return, so he’s worth monitoring during spring training. If his velocity is back, he’ll become a prime target at a discounted price.

Meh, Kyle Gibson posting a 5.05 ERA, but still underperformed an unsightly 4.46 xERA. Camden Yards is a better home than Citizens Bank after the changes at the former turned it into one of the tougher places to hit a home run. What’s interesting here is that his luck metrics weren’t that out of line with his career. The biggest issue seems to be his LOB%, which should rebound, but that merely results in a low-to-mid 4.00 ERA with little upside for a 35-year-old.

It’s pretty surprising to find Aaron Nola on this list considering he fully rebounded off his unlucky 2021 to post the second lowest ERA of his career. With a league matching BABIP, and better than league average HR/FB rate and LOB%, it’s again surprising to find his xERA well below his actual mark. Unfortunately, I wouldn’t expect much better results here as I think he’s at his full season strikeout rate peak, and there’s limited room to reduce his walk rate any further. Odds are, that 3.6% walk rate is going back up. It still leaves him with a solid mark, but going to make it difficult to produce a sub-3.00 ERA absent of some good fortune.

Welp, guess that 2018 season ain’t happening again for Germán Márquez. Obviously, pitching half your games at Coors Field makes it mighty difficult. Unsurprisingly, he has posted a 5.08 ERA at home over his career, versus a 3.76 mark away. Interestingly, he hasn’t massively underperformed his xERA marks like you might think playing in one of the league’s most hitter friendly parks. Still, a declining strikeout rate and SwStk% is a major concern, but what’s odd is it wasn’t driven by a drop in velocity. If he ever managed to get out of Colorado, I would be much more excited about a potential rebound here, but the downside is just too large to speculate on any sort of bounceback.

Having just posted the lowest strikeout rate of his career over a full season, it would appear that Corey Kluber’s days of remaining a strong fantasy asset are officially over. You can’t be surprised by the 36-year-old, as most pitchers are in their decline phase at that age. One of the issues is he’s lost velocity, as his sinker’s average velocity has dropped below 90 MPH for the first time, declining near two miles per hour compared to 2021. He never had a great fastball to begin with, so dropping below that 90 MPH baseline makes him even more reliant on his breakers. Like Nola, there’s no more room to improve that 3% walk rate, so unless he finds some lost velocity and gets that strikeout rate back up, he could be in for another season that doesn’t help fantasy owners.