Bryce Harper is 21 years old, launched more home runs during his age 19 and 20 seasons (42) than any hitter since Tony Conigliaro a half-century ago, and racked up as many Wins Above Replacement over that period (nine) as Ty Cobb. Yet, for all of Harper's early-career accomplishments -- or perhaps because of them -- we like to nit-pick his performance. Can Harper, limited to 118 games last year due to a left knee injury, learn to avoid brain-rattling outfield collisions while retaining his competitive fire? Why hasn't he joined fellow phenom prospect Mike Trout among the game's truly elite? Was it really such a good idea for Harper to challenge Jesus Montero to an eating contest during the offseason? (He lost, apparently.)
With the focus on Harper's playing style and off-field plate discipline, some might have overlooked his across-the-board offensive improvement in 2013. Harper boosted his batting average (from .270 as a rookie in 2012 to .274), on-base percentage (.340 to .368) and slugging percentage (.477 to .486) while also sharpening his strike-zone control (his walk-to-strikeout ratio climbed from 0.47 to 0.65). His park-and-league-adjusted OPS spiked from 18 percent above average to 33 percent above average. By any measure, Harper's bat became even more lethal in 2013.
How, exactly, did Harper post arguably the best offensive showing by an age-20 corner outfielder since Tony C? Here's a closer look at his gains in controlling the zone and clubbing pitches deeper into the gaps.
No More Trouble with the Curve
Harper increased his OBP by nearly 30 points thanks to a more refined plate approach in 2013. After walking in 9.4% of his plate appearances as a rookie, Harper drew ball four 12.3% of the time last year. Granted, pitchers tiptoed around the Nationals slugger, throwing him fewer pitches in the strike zone last season (41.2%) than in 2012 (42.3%). Only Pablo Sandoval (37.2%) got a lower rate of in-zone offerings among players batting at least 400 times in 2013. Still, to Harper's credit, he did a better job of laying off those pitches tossed off the corners and in the dirt.
Harper chased less often no matter the pitch type, but he made the biggest strides in containing himself versus curveballs. While he chased hooks at the fifth-highest clips among all National League hitters in 2012, Harper displayed above-average discipline in 2013.
Harper's chase rate by pitch type, 2012-13
Harper lunged at plenty of low-and-away curveballs as a rookie. Last year, he let pitches thrown below the knees go by. His chase rate on low curves plummeted, from 45.6% in 2012 to 28.3% in 2013.
Harper's swing rate vs. curveballs, 2012
Harper's swing rate vs. curveballs, 2013
Harper also connected on pitches more often last year, paring his strikeout rate from 20.1% to 18.9%. While he whiffed more often against changeups, he more than offset that uptick by making more contact versus fastballs and breaking stuff. Once again, Harper improved most against curveballs.
Harper's miss rate by pitch type, 2012-13
Deeper drives, More Pull Shots
At first blush, Harper's already-impressive pop didn't improve much from 2012 to 2013. His Isolated Power (slugging percentage minus batting average) barely budged, from .206 to .212. Dig a little deeper, though, and Harper looks primed to hit bombs and blow kisses more often in 2014.
Harper swatted fly balls an average of 273 feet as a rookie, which was slightly above the MLB average (269 feet) and in the same range as second basemen Jose Altuve and Neil Walker. Last year, Harper hit fly balls an average of 285 feet -- the same as David Ortiz and Joey Votto, and farther than Trout (281 feet). That helps explain why Harper's home run per fly ball rate climbed from 15.7% to 19.2%, cracking the top 20 among MLB hitters.
He also put the ball in play to the opposite field less often in 2013 (28.5%) than in 2012 (36.8%), instead cranking more pitches to center field and the pull side. Like many hitters, Harper does more damage when he pulls the ball (career .853 slugging percentage) or lines a pitch to center field (.564) than when he goes oppo (.484). With Harper hitting deeper -- and more frequent -- shots to center field and the pull side, he could top 30 homers next year.
Bryce Harper isn't at Mike Trout's level, at least not yet. And yeah, he does need to stop face-planting into fences. But let's not forget that he's already a star-caliber major leaguer despite being the same age as this year's top college prospects, and he's constantly improving. Let's stop nit-picking, and enjoy the beginnings of an inner-circle Cooperstown career.