Breaking Down Bryce Harper's Homers

As the Nationals chase 100 wins, Bryce Harper has an outside shot of becoming baseball's all-time teenage home run champ. With 21 bombs, Harper has already passed the likes of Mickey Mantle (13 in 1951), Ken Griffey Jr. (16 in 1989) and Mel Ott (18 in 1928). Next up is Tony Conigliaro, who hit 24 homers back in 1964. How has Harper put himself one power surge away from Tony C.'s record? Here's a quick breakdown of Harper's homers.

• The lefty-hitting Harper has gone deep 15 times against right-handed pitchers, and six times versus lefties.
• He has done more damage on non-fastballs (12 home runs) than fastballs (nine). Harper has nine homers against fastballs/sinkers, four against changeups, three apiece versus sliders and cutters, and two on curveballs. Perhaps it shouldn't surprise us that Harper has more big flies against non-fastballs, considering that he has seen the second-lowest percentage of fastballs among all qualified MLB hitters:

Lowest fastball percentage seen among qualified hitters, 2012

Batter	Fastball Pct.
Pedro Alvarez	38.1%
Bryce Harper	38.3%
Cameron Maybin	38.5%
Alfonso Soriano	38.9%
Ike Davis	39.3%
Chris Johnson	40.2%
Justin Upton	40.5%
Josh Hamilton	40.6%
Dan Uggla	40.7%
Jesus Montero	40.9%

• Harper hasn't had much use for the opposite field, as his homer spray chart shows:

 He has hit 12 HR to the pull side, six to center field and three to left field.

• While Harper's pull power would lead you to believe that he hit most of his homers  against inside stuff, he actually has more taters on outside pitches (nine) than inside or middle offerings (six apiece).
• Six of Harper's homers have come on the first pitch of an at-bat. The only NL hitters with more first-pitch home runs are Ike Davis (11), Jay Bruce (10), Carlos Beltran (10), Ryan Braun (nine), Adam LaRoche (eight) and Matt Holliday (seven).

Harper Hampered By Low Stuff

With Mike Trout going all Willie Mays on the American League and his precocious NL counterpart struggling, the Bryce Harper hype machine has died down considerably. Harper's OPS+ has dipped to exactly league average (100). That's still amazing for a 19-year-old -- just five teenagers in MLB history (Mel Ott, Tony Conigliaro, Johnny Lush, Ken Griffey Jr. and Edgar Renteria) have posted better batting marks while getting 400-plus plate appearances in a season. But Harper has undoubtedly been hampered by low stuff during his rookie year.

Here's Harper's contact rate by pitch location, and then the league average. He's connecting often on high and middle pitches. Stuff at the knees is another matter entirely:

Harper's contact rate by pitch location, 2012

Average contact rate by pitch location, 2012

Harper's miss rate on high pitches (17.3%) is much lower than the MLB average (21%). He whiffs more than most on middle pitches (15.6% versus the 12.9% average), but you'll see in a moment that he more than makes up for it with epic power.

On low pitches, however, Harper's 41.2% miss rate is far north of the 31.6% MLB average. And when he does make contact, it's rarely the kind of hellacious, seam-ripping hit we've come to expect:

Harper's slugging percentage by pitch location, 2012

Average slugging percentage by pitch location, 2012

He's slugging .444 against high pitches (.392 average) and a robust .604 against middle stuff (.481 average). Yet when pitchers pound him at the knees, Harper has been one of the worst in the game:

Lowest slugging percentage vs. low pitches, 2012

Batter	Slugging Pct.
Elvis Andrus	.134
Brandon Crawford	.147
Jamey Carroll	.156
Rickie Weeks	.159
Carlos Pena	.178
Cameron Maybin	.208
Corey Hart	.220
Bryce Harper	.236
Michael Bourn	.239
Jason Kipnis	.242
MLB Avg.	.335

Opponents may be picking up on Harper's low-ball struggles: He has seen a season-high 47% of pitches thrown down in the zone this month (the MLB average is a little under 42%; Harper saw low pitches 41.4% of the time from April-July). There's little reason to think Washington's slugging wunderkind won't eventually figure out how to crush pitches thrown down. But in the meantime, going low is a winning strategy against Harper.

Pitchers Approaching Harper, Trout Far Differently

The careers of Bryce Harper and Mike Trout will forever be linked. The game's top two prospects entering the season spur endless debate -- will Harper's pure power or Trout's five-tool game ultimately prove more valuable? So far in 2012, both are raking. Harper has a 141 OPS+ 125 plate appearances, and Trout has a 148 OPS+ in 129 plate appearances. While the 19-year-old Harper and 20-year-old Trout are each having historically great seasons for players not yet legally able to buy a brew, the way pitchers are approaching them couldn't be any more different.

With Harper having already popped four home runs and batting in the meat of the Nationals' order, pitchers are reluctant to throw him strikes. Trout, sitting atop the Angels' lineup, has seen many more strikes:

Player	Zone Pct.
Harper	43.3
Trout	51
MLB Avg.	48

As you might expect from those above numbers, Harper is getting plenty of off-speed stuff. In fact, he has seen to lowest percentage of fastballs (two-seam and four-seam) among all major league hitters with at least 100 plate appearances:

Player	Pct. Fastballs Seen
Bryce Harper	31.8%
Bryan LaHair	33.0%
Brandon Belt	33.9%
Ike Davis	35.4%
Ian Stewart	35.7%
Geovany Soto	36.1%
Cameron Maybin	37.3%
Carlos Ruiz	37.7%
Alfonso Soriano	38.2%
Pedro Alvarez	38.3%

Trout, meanwhile, has seen more fastballs than any hitter in the game with at least 100 plate appearances:

Player	Pct. Fastballs Seen
Mike Trout	62.8%
Alberto Callaspo	62.3%
Maicer Izturis	61.2%
Jemile Weeks	58.9%
Chone Figgins	58.9%
Humberto Quintero	56.9%
Juan Pierre	56.1%
Andy Dirks	55.9%
Vernon Wells	55.8%
Emilio Bonifacio	55.6%

So far, giving Harper off-speed stuff off the plate and Trout an abundance of in-zone fastballs hasn't worked for pitchers. Luckily (or should I say unfortunately?), opponents have a good 15-20 years to figure out how to return these prodigies to the dugout.