Starting Pitcher SIERA Underperformers — Aug 18, 2022

Yesterday, I identified and discussed five fantasy relevant hitters who have underperformed their xwOBA marks the most. Now let’s flip to starting pitchers for a potential rest of season trade target list by identifying those that have underperformed their SIERA marks the most. I’m only including pitchers who are healthy and not on the IL.

It’s debatable whether you would consider Patrick Corbin still fantasy relevant, but a 4.29 SIERA suggests that he should be, at least in NL-Only leagues. Yes, his strikeout rate is at its lowest since 2016, as is his SwStk%. But his pitch mix hasn’t significantly changed and his velocity is fine. His slider has simply gone from elite to merely above average. And with a bad fastball in terms of generating whiffs, he has found it more difficult to get to strike three without that elite slider.

But check out that BABIP! That’s highest in baseball among any pitcher with at least 50 innings. Corbin should be used to worse than average BABIP marks, as his career average stands at an inflated .316 and just twice has he posted a mark below .300. But .378 is obviously a career worst and just absurd. Sure, his LD% is worse than league average, but in no way explains the insane BABIP. All those hits falling in have pushed down his LOB% to just 61.7%, which is lowest among pitchers with at least 70 innings pitched (fifth lowest among 50+). To be honest, I don’t see anything here that would make me want to roster him, even in deep leagues, given his weak strikeout rate and the fact he has posted mid-4.00 SIERA marks three straight years, with an ERA no lower than 4.66. But he should certainly be better the rest of the way if that matters!

Man, Jose Berrios has to be one of the most disappointing starting pitchers this season. However, this doesn’t seem like the same Berrios owners thought they were drafting. His strikeout rate has slid to its lowest mark since his 2016 debut, as has his SwStk%. His velocity is fine, and while Pitch Info Pitch Type believes he has swapped his curve for a slider, the Pitch Type box doesn’t believe any such swap has occurred. The velocity, movement, and SwStk% on the pitch are pretty close to his curve last year, so I would guess it’s the same pitch and Pitch Info is just confused.

The thing with Berrios is he’s never had an elite pitch. He always had a mishmash of average to slightly above average whiff pitches, but generated a high rate of called strikes to compensate. That’s not the type of pitcher I like rostering. The called strikes are still there, but his already below average SwStk% has fallen further.

So clearly his skills have softened. However, it’s the highest BABIP since his 2016 debut and career worst HR/FB rate that have really done him in. If anything, his BABIP should be better than normal, as his LD% has declined from the last two seasons and is just below his career average, while his FB% is sitting at a career high, which should usually lead to more easy outs. It’s also bizarre to see a career worst HR/FB rate this season of all years, given that home runs are down.

Overall, I’ve never been enthused by Berrios to begin with, and his skills certainly don’t excite me now. But, this seems like an obvious case of some bad fortune that should reverse over the rest of the way. I wouldn’t go expecting vintage Berrios though.

As a Lucas Giolito owner in two of three leagues, it’s been a frustrating and surprising season so far. His SIERA stands almost identical to last year, despite a drop in strikeout rate and increase in walk rate, yet his BABIP has ballooned, raising his ERA to marks we haven’t seen since before he broke out. One concern is a decline in SwStk% to the lowest we’ve seen since he became good. While he has offset some of the drop by generating a career high rate of called strikes, it hasn’t been enough to prevent his strikeout rate from falling.

Coinciding with his 2019 breakout was a velocity spike to over 94 MPH. He maintained that for three years, but it’s dropped this year to just 93.1 MPH. Amazingly, he has only recorded two games in which his fastball velocity averaged at least 94 MPH, despite averaging that for the entire season last year. What had been concerning is the two games when he averaged less than 92 MPH with his fastball recently, but the fact he was back to 93.5 MPH during his last game is a good sign. It shouldn’t be a surprise then that the SwStk% on his four-seamer has fallen into single digits for the first time during his breakout years, while both his changeup and slider have also induced a lower rate of swings and misses.

Like Berrios above, it’s clear that Giolito’s skills have deteriorated this year, and a drop in velocity could explain a lot of it. However, it cannot possibly explain the inflated .356 BABIP, which is significantly above his .277 career mark and his previous career worst of .273. I’m not selling low here and would be a cautious buyer.

I was excited about Josiah Gray this year given his awesome curveball-slider combo last year that both generated SwStk% marks over 20%. While his slider has remained elite, his curve’s SwStk% has fallen into the low teens. He also still throws his changeup for some reason, even though it has recorded a weak 1.8% SwStk%. He needs to just ditch that pitch.

Though his SwStk% has fallen from last year, better luck and an increased called strike rate has pushed up his strikeout rate. However, the problem stems from all the fly balls he allows, combined with a devastating case of gopheritis. When you’re allowing such a high rate of flies, you cannot possibly afford to also allow a high HR/FB rate. But that’s exactly what’s happened here, as he ranks second in baseball among pitchers with at least 70 innings pitched in HR/FB rate. That has led to a crazy 2.36 HR/9, which is actually slightly better than last year’s mark somehow. That HR/9 is highest among the 70+ innings crop.

It’s interesting here because despite the high HR/FB, he has maintained a much lower than average BABIP, thanks to all the flies, and even more surprisingly, has posted a LOB% over 80%. That’s hard to do when so many balls in play are leaving the park to clear the bases.

The toughest part about starting Gray is his inconsistency. The homers allowed really makes his results unpredictable from game to game, so you can’t just fall back on the “he’s been pitching well lately” card that many fantasy owners play. As an owner in one league, I’ve generally started him only during two-start weeks and if he has a weak opponent when only starting once. He should be better though if he could start keeping more of those flies inside the park. You would think this would be the season to do it!

I have to pat myself on the back, because in my AL-Only keeper league, Sean Manaea was a prime trade target as he was in the last year of his contract and was pretty cheap. The rebuilding team he was rostered on had no use for him and I wouldn’t have increased my team salary much, if at all (we have an in-season cap). So I strongly considered making an offer, but ultimately decided against it due to his ominous velocity trend. So far, it turned out to be a good decision, as he has been awful since I made the decision not to make an offer for him.

His sinker averaged just 89.9 MPH in mid-July and then just 88.9 MPH during his last start. For the season, his velocity is down more than one mile per hour. It hasn’t significantly affected his strikeout rate or SwStk%, but it’s getting near dangerous territory where you expect it might start to. Oddly, his walk rate is up to a career worst, which you wouldn’t expect with his velocity being down. It makes you wonder if something is wrong physically.

Manaea SIERA underperformance is primarily driven by a sub-70% LOB%. If you exclude the short 2020 season, it’s at a career worst, compared to a career average that is close to league average. So this isn’t normal for him. If the velocity was normal and not down from last year or sub-90 MPH in his last start, I would absolutely be targeting him in a trade. Since that’s not the case, I am still shying away.