2018 June Potential Starting Pitcher xwOBA Regressors

Back from Portugal! Thankfully, technology is amazing and I haven’t missed a baseball beat. Before I left, I listed and discussed the starting pitchers who had posted significantly worse wOBA against marks than their Statcast xwOBA marks. So today I’ll look at the pitchers on the other side of the coin, those who have most outperformed their xwOBA marks, and therefore may be in for some serious regression.

Remember that xwOBA fails to account for home ballpark, defensive support, quality and opposition, and perhaps other factors I’m not able to come up with at the moment. It’s why I stick to the extremes, as even with all factors accounted for, it’s highly likely these guys are still due for the same directional move in wOBA, though perhaps not to the same degree.

Dan Straily tops the list of the lucky folk, posting a wOBA nearly a full 100 points below his xwOBA. That’s impressive! He has accomplished this feat thanks to a .200 BABIP, which is clearly some magic act given that his LD% sits at an inflated 29.7%. His strikeout and walk rates are disgusting as well, so you’re playing with fire if he’s in your lineup because of that currently shiny ERA. It won’t stay shiny for much longer.

Uh oh, Sean Manaea is not the man I wanted to find here, considering I own him in a bunch of leagues. Despite posting another double digit SwStk%, his strikeout rate has remained below average, and only a stronger walk rate has helped keep his K-BB% in line. A .225 BABIP obviously won’t last, so I’m nervous here. Of course, the time to sell high was many starts ago, either just after his no-hitter or the start after. Since, he’s allowed four runs three times, and six in his latest outing. You always worry about health, but I would wait for another good outing or a pair of good outings before seeking to sell him.

For his career, Francisco Liriano owns essentially a league average BABIP of .298, but this year, it sits at just .220. That’s all you need to know to understand why he has outperformed his xwOBA to such a degree. His skills are nearly identical to last year, but this BABIP is what has pushed his ERA down by nearly two runs. You shouldn’t be tempting fate, even in AL Only leagues, where he should be firmly on your trade block or your bench (better yet, in the free agent pool so he could wreck your competitor’s ratios).

For a second straight season, Daniel Mengden has posted results far better than his skills support. This season, he continues to strikeout few, while displaying elite control, but has gotten by thanks to a low BABIP. You can’t even argue soft contact, as xwOBA literally accounts for that, and his Hard% is an inflated 38.2%, well above the league average. I’m selling him for anything in AL-Only and wouldn’t touch him in shallower.

This hasn’t been the Michael Wacha rebound you may have thought. While a .278 BABIP and 8.7% HR/FB is more in line with his good ERA years, xwOBA suggests that the quality of contact he has allowed are deserving of far worse results. His walk rate is also at a career worst and he’s allowing line drives at an insane 30.8% clip. Now seems like an excellent time to sell high, as he hasn’t allowed more than two runs since his third start of the season.

It’s scary when you appear on this list and your ERA is already inflated at 4.54. I know James Shields is still sitting on free agency in one of my two AL-Only leagues (he’s actually on a team in AL Tout), but there’s bound to be some more of you who own him. Don’t do that to yourself.

That xwOBA mark is still well below average for Jeremy Hellickson, so although he has been fortunate, he has been legitimately good, and much better than his recent disastrous seasons. He’s inducing more grounders than ever, and yet also generating a ton of pop-ups, which is a rare combination. While he’s unlikely to maintain a .245 BABIP, remember that he used to be a low BABIP king, and even posted a .246 mark last year when he was beyond awful. He should handily outperform his rest of season ERA projection and probably earn a bit of NL-Only value.

Jaime Barria has been a surprise positive for AL-Only leaguers over six starts, but the good times aren’t likely to last, since he’s not going to maintain a .247 BABIP all year. Oddly, his SwStk% is a strong 11.8%, yet he has only managed a 19.4% strikeout rate. Perhaps there’s some upside there, which could hold off some ERA regression when his BABIP rises.

Nope, the Reynaldo Lopez breakout is not happening, despite what his 2.93 ERA might lead you to believe. Both his strikeout and walk rates are worse than average and combine for a weak 6.4% K-BB%, and he’s getting by thanks to a .218 BABIP and 8.3% HR/FB, despite pitching in a favorable home run park. He’s a prime sell high guy considering his former prospect status, which gives the impression that he’s enjoying that anticipated breakout.