2023 Projection Showdown — THE BAT vs Steamer Starting Pitcher ERA, Part 1

Today, I’ll continue the starting pitcher side of the 2023 projection showdown, pitting THE BAT against Steamer projections. This time, we’ll hop on over to ERA. This is probably what we all pay most attention to and it’s likely what keeps a pitcher in his team’s rotation. There are a number of drivers of a pitcher’s ERA, such as skills like strikeout and walk rates, along with luck-influenced metrics like BABIP, LOB%, and HR/FB rate. So let’s begin by reviewing the starting pitchers that THE BAT is more bullish on for ERA compared to Steamer. It’s important to note that THE BAT’s ERA projections are meaningfully higher than Steamer, so you’ll see smaller differences among its favorites, compared with Steamer’s favorites that will be revealed on Thursday.

Talk about luck metrics and Julio Urías, Dodgers fans, and his fantasy owners over the years, would laugh. He has made a career out of significantly overperforming his SIERA mark, as his ERA sits more than a full run below. That’s crazy! He’s done it thanks to a far better than league average BABIP and HR/FB rate, along with a high LOB%. It’s only been about 600 innings though, so the odds are there’s some luck involved here. But it’s clear he must have some sort of skill in limiting the type of contact that results in hits falling in and fly balls sailing over the wall. This is the type of pitcher Steamer notoriously has trouble with as it typically regresses those luck metrics, especially BABIP, back toward league average. Sure enough, it’s easily the highest forecast among systems, while THE BAT is actually projecting a mark just below his career average.

A look at Statcast’s xERA could be helpful here as it uses actual batted ball data to compute an expected ERA. Here, Urías has still overperformed every single year! However, the overperformance appears clearly less dramatic than his SIERA underperformance, suggesting there’s some skill here. That said, I have no idea what he could be doing to consistently overperform his xERA, but perhaps he’s just had that perfect combo of skill and luck. Someone needs to get luckiest, maybe it’s him! I think all the systems are still assuming a healthy amount of regression, but THE BAT acknowledges Urías’ BABIP suppression skills are real, while Steamer assumes none of it is. I’m going to go with THE BAT on this one, as the ERA jump is enough to think he could still regress substantially and yet finish with an ERA closer to that system.

It’s only been two seasons, but Alek Manoah has already massive overperformed his SIERA, thanks to a microscopic BABIP, better than league average HR/FB rate, and a skyhigh LOB%. His xERA was only barely higher than his 2021 debut ERA, and was nearly identical last season, but his ERA dropped about a full run. Seems pretty clear that last year required lots of good fortune. But xERA suggests he’s still a 3.30 ERA type guy, as opposed to the 3.80+ that SIERA calculates. Once again, we find a big difference coming from the BABIP forecasts, with Steamer all the way up at .286, while the second highest system is at .272. On the other hand, THE BAT is at .266, which isn’t even the lowest among systems. So it’s forecasting regression, but still acknowledging there’s some skill here. Given the consistent xERA that essentially justifies the low BABIP, I’m going with THE BAT again.

Despite featuring a fastball and sinker combo that consistently averages 97-98 MPH, Sandy Alcantara hasn’t really converted that elite velocity into a high strikeout rate. It hasn’t mattered though, as he owns a career 3.10 and posted a significantly better than league average BABIP that allowed him to massively overperform his career 4.19 SIERA. Guess where the systems differ. That’s right – BABIP! Steamer is actually sitting above the league average with its .300 forecast, while THE BAT is expecting a mark that would represent a career worst, and well above his career average. As a ground ball pitcher, it’s not often you see such BABIP suppression. He does own an interesting low-LD% skill though, so that helps offset the higher BABIP from all those grounders. Checking in on his xERA, he’s overperformed that mark every season as well! So again, he’s either been quite lucky, is doing something that doesn’t even show up in the batted ball data, or a little bit of both. I think THE BAT assumes enough regression here that I’m going to bet on that system proving closer, as his BABIP has been so consistently low that there must be some sort of skill, which Steamer is not a believer in.

Gotta love projection systems disagreeing on 15-year veteran Clayton Kershaw! As I covered on Monday, THE BAT is much more bullish on his strikeout rate, which I think will prover closer than Steamer’s more pessimistic projection. Another big discrepancy comes from…you guessed it…BABIP. Amazingly, Steamer isn’t highest with its .299 forecast, but ATC is with a .300 mark. Those are incredibly bearish projections considering he hasn’t posted a BABIP above .289 (posted in 2021) since his 2008 debut, when he posted a .320 mark! On the other hand, THE BAT’s .279 projection is kind of bearish on its own, as it would represent his second highest mark since 2015. I see no reason to believe his BABIP is suddenly headed somewhere it’s rarely been and also believe in THE BAT’s strikeout rate projection more, so I’m going with THE BAT’s ERA projection as ultimately proving closer.

Cristian Javier also made THE BAT’s strikeout rate favorites list. I kind of throw my hands up not fully understanding how he has managed such strong strikeout rates. But it’s hard to argue with the results, which is why I thought THE BAT’s strikeout rate projection would prove closer than Steamer’s more bearish forecast. There’s a big BABIP difference here too, of course. Javier has posted some incredibly low marks throughout his short career, and he sits with just a .223 career mark. A lot of that is because he’s an extreme fly ball pitcher who also generates pop-ups. But with only about a season and a half of innings under his belt, it’s too early to be sure he’s this good at suppressing BABIP. Amazingly, he has actually underperformed his xERA in two of three seasons! So based on batted ball data, that extreme fly ball rate genuinely results in few hits on balls in play. It suggests that all systems might be too bearish on his ERA. That being the case, I’m going to once again bet on THE BAT’s ERA projection proving closer, as it’s less bearish than Steamer.

Tyler Anderson appeared second in THE BAT’s strikeout rate favorites list, a mark I sided with compared to Steamer. Aside from the strikeout rate difference, we find a BABIP gap as usual. Here, THE BAT is forecasting the lowest mark, and actually below his career average, while Steamer is highest, and just above his career average. Checking in on what xERA thinks, surprisingly he wasn’t as lucky as he appeared to be by SIERA last year. He certainly did overperform his xERA, but nowhere near the same degree. I think his ERA might actually finish in the middle of the two forecasts, but perhaps a bit closer to THE BAT’s less bearish projection.