Starting Pitcher GB% Surgers

The batted ball distribution metrics, for both pitchers and hitters, are some of the most stable statistics around. A pitcher’s ground ball rate stabilizes after just 70 batters faced, which is basically just three starts. So what this means is that when we see a significant change in a player’s batted ball mix, we have to take it seriously. Let’s take a look at the starting pitcher’s who have enjoyed the largest surges in their ground ball rates and see if we could uncover an explanation.

Name 2015 GB% 2014 GB% Diff
Michael Pineda 53.2% 39.1% 14.1%
Gio Gonzalez 57.9% 44.8% 13.1%
Ubaldo Jimenez 54.0% 41.4% 12.6%
Shelby Miller 50.3% 39.9% 10.4%
Jake Odorizzi 40.1% 29.9% 10.2%
Nick Martinez 43.3% 33.6% 9.7%
Danny Salazar 43.8% 34.4% 9.4%
Drew Hutchison 44.2% 36.1% 8.1%
Jeremy Hellickson 44.6% 36.5% 8.1%

It’s not enough that Pineda has combined absolutely pinpoint control with a strong ability to induce swings and misses. He has taken his overall skill set to entirely new heights by turning from a fly ball pitcher into a ground ball one. All of his pitches have induced grounders more frequently than in the past and a quick look at his heat maps shows us that he has indeed been working lower in the zone. Health is the only thing holding him back from potentially being a top five or 10 starting pitcher the rest of the way.

Gio Gonzalez’s pitch mix is very similar to last season, with the only difference coming from throwing more two-seamers rather than four-seamers. But, he’s thrown two-seamers at similar rates in the past and still hasn’t sniffed this high a ground ball rate. Like Pineda, all of his pitches are generating grounders at higher rates than he typically has, while the move to more two-seamers has helped given the huge disparity in grounder rate it induces versus the four-seamer.

Despite continued velocity erosion, Ubaldo Jimenez has rediscovered his ground ball inducing ways of yesteryear. Not since 2009 has he posted a ground ball rate above 50%. Like Gio above, Jimenez is using his two-seamer more often at the expense of his four-seamer, but unlike Gio, the two fastballs have near identical career ground ball rates and are similar again this season. The real difference has been from his slider, which has induced a grounder nearly 67% of the time versus a 39% career mark.

Upon his move to Atlanta, Shelby Miller has become quite a different pitcher. He has swapped some four-seamers for two-seamers and thrown significantly more cutters at the expense of his curve ball. Both the two-seamer and cutter are his groundballiest pitches, so this change in mix provides quite the easy explanation. It has helped his skills bounce back, but unfortunately he’s benefiting from an enormous heaping of good fortune.

Jake Odorizzi is easy — he’s throwing more of his cutter and splitter/change instead of his four-seamer and slider. His ground ball rate remains below the league average, but at least he won’t be as homer prone as he was in the past.

All of Danny Salazar’s pitches, with the exception of his four-seamer, are generating a higher rate of grounders. And according to our PITCHf/x data, his new curve has apparently induced a grounder half the time and a line drive the other half. Of course, those additional grounders haven’t mattered much yet, as his HR/FB rate sits at an inflated 17.9% mark, pushing his HR/9 rate at a career high 1.44. But that’s going to drop, of course, and that 28.6% K%-BB% is going to make him shine.





Mike Podhorzer is the 2015 Fantasy Sports Writers Association Baseball Writer of the Year. He produces player projections using his own forecasting system and is the author of the eBook Projecting X 2.0: How to Forecast Baseball Player Performance, which teaches you how to project players yourself. His projections helped him win the inaugural 2013 Tout Wars mixed draft league. Follow Mike on Twitter @MikePodhorzer and contact him via email.

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Mike W.
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Mike W.

Judging by this list, is it safe to assume better days are ahead for Drew Hutchinson or will be continue to be frustratingly uneven with his performance?If he can keep getting more ground balls, that would be a big help considering the home park he pitches in and his tendency to sometimes get killed by the Home Run.

Emcee Peepants
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Emcee Peepants

Hutchison is up to 46% after yesterday’s start. His FIP, xFIP, and SIERA are all under 4, so it seems at least part of his problem is BABIP luck. But he has been maddeningly inconsistent and hard to know when he will crap the bed.