Aroldis Chapman on Target

Right now, Aroldis Chapman is scary. And not scary in the "might decapitate some dude in the third row" way that he was last season. The lefty with the turbo fastball has stepped up with Ryan Madson out following Tommy John surgery, striking out fifteen batters in eight innings pitched. Perhaps more importantly, Chapman hasn't given up a single walk after issuing 7.4 BB/9 in 2011.

Chapman has made grown men with immaculate reflexes look like late-inning beer league softball players by pounding the strike zone with his fastball. His velocity is "down" a tick, but he's hitting his spots and inducing swings and misses like no other reliever in the game:

Aroldis Chapman's fastball

Year	Fastball Zone Pct.	Fastball Miss Pct.	Velocity
2011	45.3	31.2	98.1
2012	67.9	47.6	97.1
Avg. RP	51.9	18.2	91.6 (for LHP)

Chapman's fastball zone percentage is fourth-highest among MLB relievers, behind just Javy Guerra, Fernando Salas and Greg Holland. And no other 'pen arm comes close to Chapman in whiffs: Kelvin Herrera (36%) is a distant second in fastball miss percentage.  

In 2011, Chapman often missed to his glove side and high out of the zone with his fastball...

Chapman's fastball location, 2011

Early on in 2012, however, Chapman has pelted hitters with high fastballs catching the plate: 

Chapman's fastball location, 2012

Opponents are a combined 2-for-20 against Chapman's fastball in 2012. Props to Jose Reyes, the only batter to get an extra-base hit on a Chapman heater (he tripled back on April 8).

Chapman's game revolves around his fastball, which he has thrown nearly three-quarters of the time. But he has also done a better job of locating his slider and changeup in 2012 (65 Zone%) than in 2011 (37%). It's only mid-April. But there might not be a harder late-inning assignment right now than squaring up Chapman.