Turn left: Pull power key to Goldy's 2017

D-backs slugger used left side of field more in latest MVP-caliber season

Turn left: Pull power key to Goldy's 2017

If Paul Goldschmidt's 2017 season had to be distilled into a single swing, the home run he hit off Wade Davis on Aug. 3 would be as fitting as any.

With the D-backs and Cubs tied in the ninth inning, one of the game's best closers pumped in a 96.3 mph fastball, knee-high and on the inside edge of the strike zone. From his distinctive stance -- hands and elbows high, bat angled down across his back shoulder -- Goldschmidt tilted over the plate and drew his hands down; with a quick rotation of his hips, a slight uppercut and a follow-through as short and stiff-armed as a golfer hitting out of deep rough, he drove the ball 101.0 mph, a Statcast™-projected 428 feet to the back of Wrigley Field's left-center-field bleachers.

Goldschmidt's swing has driven the D-backs for years, and this season it helped carry them into the postseason for the first time since he was a rookie in 2011. It's earned him another chance at the National League Most Valuable Player Award -- on Monday, he was named an NL MVP finalist for the third time in the last five years, along with the Marlins' Giancarlo Stanton and the Reds' Joey Votto. But in 2017, seeking his first career MVP trophy after finishing as the runner-up in 2013 and '15, Goldschmidt turned his swing in a new direction: left field.

The home run off Davis was one of many Goldschmidt launched to the pull half of the park, which he took advantage of like never before. Thirty-two of his 38 home runs (a career high-tying 36 in the regular season, plus two more in the postseason) were hit to the left of dead center. He had never hit so many homers to the left half of the field in any season of his career, neither by volume nor percentage.

Goldschmidt's HR spray charts for 2013, '15 and '17

When Goldschmidt burst onto the NL MVP scene in 2013, his first time as runner-up, and when he re-entered the conversation in 2015, he did so with the well-earned reputation as a hitter who drove the ball to center field and the other way. The short, powerful swing was directed out across the diamond.

In 2017, his power rotated significantly. Statcast™ can track the difference -- Goldschmidt's fresh path to his typical elite production. It shows exactly where Goldschmidt has hit the ball hard in the three seasons since the technology's introduction in 2015. Looking at the spray charts of Goldschmidt's hard-hit balls -- those with an exit velocity of 95 mph or higher -- the shift from the right half of the field toward the left is dramatic from 2015 and '16 to 2017.

Where did it come from? In part, from Goldschmidt feasting on inside pitches -- the ones he could best turn on. Pitchers like Davis could not attack the inside part of the zone against him.

That's reflected by Goldschmidt's robust expected weighted on-base average against pitches that Statcast™ tracked as over the inner third or inside edge of the strike zone in 2017. Expected wOBA is an all-encompassing offensive metric, similar to on-base percentage, but weighted for the quality of contact a player has made on all his batted balls.

Goldschmidt's xwOBA against pitches on inner third/inside edge
2017: .434*
2016: .340
2015: .396
*3rd-highest among 186 hitters (min. 75 AB decided on inner-third/inside-edge pitches)

Goldschmidt's hard-hit rate against those inside pitches was also at its highest level since Statcast™ started tracking. In 2017, 48.1 percent of his batted balls against those pitches were hard-hit, up from 27.7 percent in 2016 and 43.9 percent in 2015. The vast majority went to the pull field.

At the same time, he also turned on more pitches over the middle of the plate. Goldschmidt's hard-hit balls against pitches in the vertical middle third of the strike zone were much more concentrated in the pull field in 2017 compared to the previous two seasons. Ten of his 12 homers on those pitches were to the pull side. In 2015 and '16, they were split evenly between fields -- 12 total homers to the left of dead center, 10 to the right.

Add that to what he did to inside pitches, and Goldschmidt this year presented a new threat. There's more than one route to perennial stardom, and Goldschmidt's changed in 2017. It tormented pitchers all year, through the regular season and into the postseason, when both of his homers were pulled and one came on a curveball that backed up high and inside. At the end of it, he's back in the place he's become a fixture: the thick of the NL MVP race.

David Adler is a reporter for MLB.com based in New York. Follow him on Twitter at @_dadler. This story was not subject to the approval of Major League Baseball or its clubs.