Starting Pitcher GB% Changers

While HR/FB rate has dropped back to its 2016 elevated level after a final spike in 2017, this season’s 12.6% mark still ranks third going back to 2002. Also keep in mind that home run rates typically rise into the summer, so this mark will likely jump back above 2016. Given the frequency of fly balls leaving the yard, it’s more important than ever that pitchers keep the ball on the ground. Some are doing that more often this season, while others are not. Let’s check in on both sides of the coin.

This is now the third season in which Jake Arrieta has posted a GB% above 50%. He posted a nearly identical mark in 2015 during his dream season, so this is nothing new. His pitch mix, though, is virtually the same as it has been since 2016, and interestingly, he’s throwing his sinker more than in 2015, but was still able to post that 50%+ GB% that season. His fastball velocity has rebounded some since last year’s decline, but it’s still far below where it sat prior to 2017. The bigger concern, however, is a SwStk% that has plummeted below the league average which has led to a sudden inability to strike out batters. None of his luck metrics scream ERA regression given his history and his low LOB% actually suggests better results. But the fewer strikeouts are still taking a bite out of his value.

Add Jose Urena to the list of hard throwers who don’t strike out a lot of hitters. That’s because neither of his secondary pitches are above average at generating whiffs. But this is his best attempt at making himself a shallow mixed league streaming option, as his GB% has jumped above 50% for the first time.

Rick Porcello really only appears here because of last year’s GB% collapse to a career low. He’s throwing his four-seamer less often, and that has been his worst ground ball pitch, so there’s an easy explanation for the rebound. He still remains down from his glory days of 50%+ ground ball rates that he posted during his first five seasons straight. He seemingly transitioned from a low strikeout, ground ball guy, to an average strikeout, average ground ball guy.

Chris Sale appears here in a similar situation to Porcello, in that he’s coming off his first sub-40% ground ball rate, though his current mark represents his highest since 2013. It’s crazy to see him repeat that 36% strikeout rate!

This isn’t the precipitous drop that it appears from the table for Dallas Keuchel. That’s because last year was a career high, and he’s sat in the mid-50% range before. There’s an easy explanation for the GB% drop — he’s throwing his sinker at the lowest rate since 2013. I’d be more worried about his lowest SwStk% since his 2012 debut and without major BABIP luck, he looks like more of an innings eater than a great ratio guy.

Gerrit Cole has clearly given up some grounders for strikeouts and its led to the best skills of his career.

I had no idea that Jhoulys Chacin is sitting with a sub-4.00 ERA for the second straight season. He’s doing that with his lowest GB% since 2012 and weak strikeout and walk rates. How much longer can he hold a sub-10% HR/FB rate, especially calling a favorable home run park home? I wouldn’t even want to own him in an NL-Only league.

So Jon Lester’s GB% has dropped to its lowest mark since 2007, his strikeout rate to its lowest since 2012, and his walk rate the highest since 2011. Sounds like a disaster of a season, right? Nope, he ERA sits pretty at just 2.25, more than two runs below his SIERA. A lot of that SIERA outperformance is thanks to the fabulous Cubs defense, who easily leads baseball in UZR/150. His luck metrics look awfully close to 2016, except that year his strikeout rate sat in the mid-20% range. His ERA won’t skyrocket toward his SIERA, but I still like he’d be able to net a much better rest of season value than he’ll earn.

I assume, as a FanGraphs reader, that none of you own Andrew Cashner, regardless of league format.

Matt Boyd was already a fly ball pitcher, but he has become an extreme one this year, which pairs poorly with his worse than average strikeout and walk rates. With a 4.65 SIERA, this is the same bad Boyd we’ve seen since his 2015 debut. You shouldn’t own him in any leagues.

Alex Wood used to be a high ground ball guy that also punched out batters and limited walks. He still limits walks, but his ground ball rate has fallen, while his strikeout rate now sits at about league average. His SwStk% still remains above 11% though, which bodes well for the future. According to our pitch info rates, he has stopped throwing his curve ball and now features a slider. His curve used to be his best ground ball pitch, while his slider sits at about the league average. His sinker usage has also reached a career low, which is understandable considering its lost considerable velocity, now humming in at just under 90 mph. Overall, his SIERA still is respectable, so I’d hold.