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Will Pineda Be Homer Prone in New York?

While Michael Pineda‘s move from Seattle to the Bronx means he should easily reach double-digit wins now that he has an offense with a pulse supporting him, the change in home ballparks isn’t as sunny. Pineda’s old home, Safeco Field, is a graveyard for power hitters and a perfect spot for a pitcher who takes to the air often. Yankee Stadium, by contrast, goes 314 feet and 318 down the lines, turning warning-track shots in other parks into souvenirs. But those fretting over how Pineda will adjust to New York should take a closer look at his 2011 season — hitters lofted far fewer pitches against him during the second half of the season. That makes his transition to the Bronx a far less scary proposition.

At first blush, Pineda’s move from Safeco to Yankee Stadium does seem troubling. Pineda tied Tampa’s Wade Davis for the seventh-lowest ground ball rate (36.3%) among qualified starting pitchers during his rookie season. And while Safeco is where deep drives go to die (the park decreases home runs by five percent for left-handed hitters compared to a neutral venue, and 18 percent for righty batters), Yankee Stadium boosts homers by 43 percent for lefties and 15 percent for righties. Pineda succeeded by peppering the middle and upper portions of the zone with four-seamers and sliders in Seattle, but that’s a dangerous strategy in a park where homers come cheap.

There’s no question that Pineda’s new digs aren’t as forgiving as the ones he left behind in Seattle. But happily, Pineda’s extreme fly ball act was really only limited to the first three months of the 2011 season. Check out his ground ball percentage by month:

Month Ground Ball Pct.
April 30.9
May 36.6
June 26.5
July 40.6
August 46.8
September 45.3

Pineda’s ground ball rate was just 30.9% in April, May and June. From July through September, however, he burned worms at a league-average 44% clip. Pineda got more grounders by throwing his high-and-heavy fastball less often and relying on his slider even more (he also threw more changeups). Both offerings had a healthy boost in ground ball rate once the calendar hit July:

Pitch Pct. Used April-June GB Pct. Pct. Used July-Sept GB Pct.
Fastball 66 27.9 55 35.1
Slider 31 44 35 55.2

Source: Joe Lefkwitz’s Pitch F/X Tool

So, why does this matter? Pineda’s second-half increase in grounders could just be a fluke, right? Maybe, but I wouldn’t bet on it. Changes in ground ball rate for pitchers become significant after about 150 plate appearances, and Pineda took on 288 batters from July through September. It’s far more likely that this trend signals a real improvement in Pineda’s grounder-getting prowess.

Some might point out that as Pineda’s ground ball rate climbed, so did his ERA (2.65 from April-June, 5.35 from July-September). But, aside from incredibly low strand rates with runners on base during the second half (something that doesn’t have predictive value), you’d be hard-pressed to say that Pineda pitched any worse. In terms of the stats that better predict future ERA than past ERA, Pineda was actually better. He struck out more batters while keeping his walk rate steady, resulting in more than a half-run drop in his xFIP:

Month K Pct. Walk Pct. xFIP
April-June 24.3 7.8 3.76
July-September 25.7 7.9 3.2

Pineda’s increased ground ball rate has implications for his road starts, too. While Rangers Ballpark is homer-happy, Pineda got the benefit of pitching in the [Insert Corporate Name Here] Coliseum and Angel Stadium in addition to Safeco while in the AL West. The Coliseum and Angel Stadium are brutal home run-hitting parks:

Park LH HR Park Factor RH HR Park Factor
Rangers Ballpark 119 114
The Coliseum 89 80
Angel Stadium 90 93

In the AL East, Pineda will have to contend with two other road parks that pump up home run production significantly:

Park LH HR Park Factor RH HR Park Factor
Camden Yards 118 123
Fenway Park 79 94
Rogers Centre 114 116
Tropicana Field 89 82

Taking a quick look at Pineda’s overall ground ball rate in 2011 is enough to make an owner think twice before spending a premium pick on a guy moving from a plum pitcher’s park to one of the game’s most homer-friendly stadiums. But that quick look obscures the month-by-month progress that Pineda made in keeping the ball down, progress that makes him better equipped to pitch in Yankee Stadium and also keep the ball in the yard when he travels to Camden and the Rogers Centre. With a more even ground ball/fly ball profile and plenty of Ks, Pineda will be just fine in New York.