2018 Starting Pitcher GB% Surgers

Though the leaguewide HR/FB rate is down (likely due in part to the cold weather), it’s clear that this fly ball revolution is here to stay. That’s bad news for fly ball pitchers, because now more of their fly balls are going to jump over the wall for a home run. The best way to keep your HR/9 rate in check is by inducing grounders. So let’s check in on the early starting pitcher ground ball rate surgers.

In the table comparing 2018 GB% to 2017 GB%, I also included LD% and FB%. Often times, pitchers are generating more grounders because of abnormally low LD% marks. Because LD% figures to rise back to historical levels, the inflated GB% is less sustainable than if the increased rate coincided with fewer fly balls. So we’re looking for GB% spike paired with FB% declines, meaning LD% is generally in line with historical averages.

Six of the seven pitchers on this list have posted suppressed LD% marks, making me think the added grounders are a fluke. We’ll dive into each anyway.

Is it really fair for Luis Severino to suddenly be a ground ball machine also? Last season, he posted an above average 50.6% GB%, but this year, he actually leads all qualified pitchers. Though some of that insane GB% is because of a low LD% that’s going to rise and reduce GB%, most of the increase is due to a an almost complete disappearance of fly balls allowed. His 13.8% FB% ranks second in baseball. Unlike many others this early, Severino’s velocity is actually up, and in his first two starts, he has thrown his slider even more frequently than ever before. The increased slider usage is the key here as it has always been his best ground ball pitch. Now, he’s throwing it more and getting more grounders than ever before with it. It’s always risky to bet on last year’s breakout pitcher, but he now looks like a strong candidate for a repeat.

Who the heck is Jarlin Garcia?! The Marlins have been trotting out a series of “who’s that?” starting pitchers, and Garcia is one of them. He topped out at a 47.6% ground ball rate in the minors, so unless he’s throwing the ball lower in the zone than he had in the past, I wouldn’t expect him to maintain a mark above 50%. With no Triple-A experience and weak minor league strikeout rates, I wouldn’t even tough him in an NL-Only league.

After winning the Cy Young award in 2016, Rick Porcello reverted right back to his typical level of perfrmance in 2017. He was once a strong ground ball guy, routinely posting GB% marks over 50%. He actually did that in his first five seasons. Since, his GB% has tumbled every season, settling in below 40% for the first time in his career last year. Is this a sign that he’s back to his ground ball ways? Unfortunately for owners, nope. His FB% has remained stagnant, sitting at the same level as it has over the previous two seasons. This is all due to a decline in LD%, which is great for BABIP, but just isn’t sustainable. Just a 6% SwStk% is also concerning.

Marco Estrada is in the same situation as Porcello, as his FB% is right where it always is. His liners have been turned into grounders, which is great so far, but it won’t last.

I’m excited about Sonny Gray. He’s the only one on the list whose LD% is normal, so his increased GB% is solely at the expense of fly balls. In addition, his velocity is up slightly and he has brought back his curve ball in a big way. The pitch has been whifftastic, to go along with a still strong slider. I’m buying.

Wellll, Patrick Corbin is a strong early candidate for second breakout pitcher of the year. He already broke out in 2013, but hasn’t been able to replicate that success since undergoing Tommy John surgery that cost him all of 2014. In just 13 innings, he has posted an eye-popping 20/2 K/BB ratio to go along with all those ground balls. Don’t expect the increased GB% to last though, as his FB% is the same as it’s always been. That’s right, he’s another LD% suppressor so far that’ll cut into his GB% when it rises. So far Corbin’s success stems from throwing his slider more than ever before (like Severino), which makes sense considering it’s elite and his best pitch.

Aaron Sanchez lost his ground ball mojo last season while he was actually healthy enough to take the mound, and although it seems like it has been recovered, a low LD% and similar FB% suggests otherwise. The big change he has made so far has been upping his usage of his changeup at the expense of his curve. His changeup was always terrible at inducing whiffs, while his curve was decent in 2016, and that’s it. This year, his curve stinks again, but that changeup has been incredible. It has generated both grounders and whiffs, which means the pitch has been elite so far. We’ll see if the pitch continues to be electric for him. While better control obviously would help, what’s really missing is strikeout ability. With his ground ball tendency, he could live with a 10% walk rate if that strikeout rate gets into the low-20% range. It’s something he hasn’t done since his 2013 debut over just 33 innings though.