Starting Pitcher ERA vs xERA — Apr 23, 2024

My favorite activity early in the season is to try to capitalize on underperforming and overperforming starting pitchers. I’ll dangle my pitchers with low ERAs whose skills don’t support it and target those who hold high ERAs despite strong skills. In the past, I’ve exclusively used SIERA to identify such pitcher groups. Today, I’ll use Statcast’s xERA, as it utilizes actual batted ball data, so not every ground ball and fly ball are equal, as they are in the SIERA equation. So let’s compare actual ERA to xERA to identify and discuss both the underperformers and overperformers. Don’t forget that any ERA estimator uses actual strikeout and walk rates, so if those metrics seem unsustainable (either on the high or low side), then the expected ERA equation isn’t going to be as helpful.

Let’s begin with the xERA underperformers, which could potentially begin your list of trade targets.

After allowing seven runs over just three innings in his last start and five runs over 4.2 innings in the one before, Garrett Crochet’s season has turned from full-on breakout to disappointing in a hurry. The good news is that his skills remain elite, with tons of swinging strikes and sterling control. Aside from the inflated HR/FB rate, much of his problem right now is the lowly 55% LOB%. There’s no chance that stays that low.

There are some concerns to be aware of. First, his fastball velocity has dropped in every start so far this year, but still remains well above the league average. Second, he has oddly reduced his slider usage his last two starts, which makes up a chunk of his whiffs induced. Finally, he has thrown very few innings in his professional career and missed the 2022 season recovering from TJ surgery. So, how many innings is he realistically going to throw this year? I think he makes for an excellent target in AL-Only and deep mixed leagues where the reduced innings won’t hurt as much, but it’ll really take a bit out of his value in shallow mixed leagues, even if I think he’ll deliver solid value when he’s actually on the mound.

It’s surprising to see Jesús Luzardo’s xERA all the way up at 4.73, so the fact that he’s supposedly been unlucky is pretty meaningless, as he still hasn’t been as good as expected. His strikeout rate is down and walk rate up, and that’s what the ERA estimators are reflecting. His velocity is fine though, while his SwStk% is right in line with his career. I figure his strikeout and walk rates will bounce back to expected rates, and given that much of his current problems stem from a low 60% LOB% which should naturally improve, he’s an obvious trade target.

Brandon Pfaadt is yet another being bitten by a low LOB%, while his CSW% suggests there’s some serious strikeout rate upside. His velocity is down a bit and he has been throwing his sinker more often this year, but the pitch has rarely generated a swinging strike. However, his slider and changeup have both been excellent at inducing whiffs, and his control remains elite. It shouldn’t take much to wrestle him away from his current owner, as it’s possible after last year’s 5.00+ ERA, those who drafted him this year are ready to give up on a breakout.

I was very wrong on Graham Ashcraft last year expecting a strikeout rate breakout after his dominant spring training performance. This year, his SwStk% has jumped and brought the strikeout rate along with it, but it’s a year too late for me! That increased strikeout rate, combined with his high GB% is intriguing and are a near match for Framber Valdez’s skill set last year. He’s not really doing anything different with his pitch mix that would explain the increased whiff rate, but his cutter has generated a significantly higher SwStk% than last year, which is driving the higher marks. I have no idea if that will continue, but that’s what’s behind the improved skills. I’m not buying here, but would be willing to pick him up if he was sitting in your free agent pool.

George Kirby’s skills are more or less identical to his first two seasons, but an insane BABIP and low LOB% have left him with a bloated ERA. It tells you just how bad that Rockies offense is that all he needed was a game at Coors to move his ERA closer to his xERA! I did think Kirby was overvalued heading into the season as his strikeout rate is mediocre, SwStk% meh, and he relies on a microscopic walk rate. That’s not my cup of tea for elite pitcher prices, but if he’s on your team, there’s absolutely nothing to worry about here. Continue starting each day/week with confidence.

What’s up with the Mariners on this list?! Luis Castillo rounds out our underperformers, and he too dominating a weak Rockies lineup at Coors to reduce the gap between his ERA and xERA. His skills are a bit odd at the moment, as both his SwStk% and CSW% sit at career lows, but his strikeout rate has jumped to the second highest mark of his career. That’s what happens over small sample sizes, not everything lines up! A concern here is that his velocity is down by more than a mile per hour from last season, and actually dropped to its lowest of the season during his last start in Colorado. That’s a bit scary. That said, he’s currently sporting an absurd .392 BABIP and obviously that’s going to come way down. Your window to buy him probably closed after his Coors start, but if you own him, monitor his velocity, while holding on.

Let’s now move on to the xERA overperformers and find out if any of these names should be dangled as trade bait.

You didn’t actually pick up Colin Rea right, RIGHT?! He has been the very definition of performing behind smoke and mirrors and should come nowhere close to your team, no matter the league size and format.

I’m really surprised to see José Berríos’ name ranking second on this list with an xERA over 4.00. That’s because I had remembered seeing his fastball velocity up early in the season and also feeling like his strikeout rate was up as well. Instead, his sinker velocity is right in line with past years, while his SwStk% and strikeout rate are down from last year and below his career averages. He has generated a career best GB%, but that should have resulted in a higher BABIP, whereas it’s now sitting at a career low. Oh, and he sports a hilarious 99.4% LOB% which means that every single batter that has reached based against him, except one, has failed to score. You can see from the three runs and two home runs allowed that only one run scored that wasn’t from the batter hitting the home run. Obviously, that won’t continue. Berríos might still remain decent all season, but he’s a prime name to dangle to see how much you can get in return. Right now, he should be valued exactly the same as he was heading into the season, so if you could get significantly more than that, you need to pull the trigger.

An 11.1% strikeout rate for Seth Lugo?! This from a guy who posted a 23.2% mark last year in his return to the rotation full-time! His velocity is down and his SwStk% sits at a low 7.6%, but he has somehow managed to suppress both hits on balls in play and home runs on fly balls. Both of those results have led to an unsustainable 88.1% LOB%. Since he posted a 3.57 ERA last year, it’s very possible owners in your league are believing in most of what he’s done to date this season. Unlike Berríos who is likely to continue to deliver some semblance of shallow mixed league value, I’m not sure that’s the case for Lugo. He could turn into a pumpkin any start and harm his fantasy teams’ ratios, so he’s an even better name to dangle to sell high.

Wowzers, Dane Dunning’s 3.91 ERA looks normal and his 4.63 SIERA is similar to last year, but his xERA is all the way up at 6.87?! Clearly, Statcast does not like the quality of contact against him so far. He is somehow sporting a .189 BABIP, which is only partially offset by the inflated 20.8% HR/FB rate. Combine all that with a double digit walk rate, and it’s been a weird start to the season. He probably won’t attract much value in return, and it’s more likely that his skills and contact quality allowed return to expected marks, pushing his xERA into normal territory. So there’s no rush here to try selling, as the value is unlikely to be there, but do be aware that a blowup with hits falling everywhere might be imminent.

Gosh I love when I start seeing guys like Tyler Anderson start getting picked up in all my leagues! Does no one see past the shiny 1.42 ERA? He is actually close to doing something I’ve never seen before — post a higher SwStk% than strikeout rate! Anyway, he’ll likely be dropped just as quickly as he was picked up once his good fortune catches up with him and reverses course. With a tiny strikeout rate, there’s nothing to hang your hat on here.

Add Paul Blackburn to the Anderson group, though he’s not as weak a pickup. At least Blackburn owns some skills worthy of deeper investigation, like a high GB%. Furthermore, his xERA suggests he has actually pitched well, despite also being lucky. That said, currently sporting a .239 BABIP, a 0% HR/FB rate since he has yet to allow a home run, and an 88% LOB%, he has won the luck trifecta game so far. The strikeout rate is below average and his supporting offense is weak, so the wins will be hard to come by once regression strikes. Seriously, give me a good middle reliever even in an AL-Only league over him, but I’d still prefer him to Anderson.

Is the 2022 Brady Singer back? Both his SIERA and xERA say yes, though obviously he’s benefited from a heap of luck so far, as evidenced by his .182 BABIP and comical 100% LOB%. The good news is he’s sporting a career best SwStk% that has driven a rebound in strikeout rate, while his GB% is up at a career best. The bad news is his sinker velocity that dropped last year hasn’t rebounded any and remains 1.7 MPH below what he recorded in 2022. Yet, his slider’s SwStk% sits at a career best, so his success will depend on that continuing. With just a four-seam/sinker and a slider, his lack of pitches makes him a risk. I’m wishy-washy on him, as he’s probably worth seeing what you can get, but is perfectly okay to hold onto and hope for a mid-to-high 3.00 ERA the rest of the way.