Will Happ-iness Continue in Philly?

The Philadelphia Phillies’ rotation has been something of a mess in 2009. The defending champs paid Adam Eaton to go far, far away during the spring. Then, projected #2 Brett Myers went down with a hip injury. Cole Hamels missed time with an elbow ailment. Jamie Moyer looked more like a pinata than a pitcher in the early going, though he has since settled down. The Phillies resorted to giving starts to the likes of Chan Ho Park, Antonio Bastardo and Rodrigo Lopez.

With all of those unpleasant developments, the emergence of lefty J.A. Happ couldn’t have come at a more opportune time. In 65.1 innings (10 starts) in the rotation, the 26 year-old Northwestern product has compiled a 3.03 ERA and a perfect 4-0 record. Should we expect Happ to keep the happy times rolling, or is he due for a fall?

J.A.’s peripherals suggest that he’s been more adequate than awesome. With 6.06 K/9, 3.17 BB/9 and a 1.38 HR/9 in the rotation, Happ has a pedestrian 4.85 Fielding Independent ERA. The homer rate looks bloated, but it’s hard to say that the figure should dip much in the coming months. Happ is an extreme flyball pitcher (career 33.6 GB% in the majors) in a ballpark that has inflated home run production by a healthy margin. His home run/flyball rate in the rotation (11.2%) is right around the league average.
Happ has benefitted from plenty of fortunate bounces on balls put in play (.247 BABIP), while stranding an inordinate 88.1% of base runners while in the rotation.

While in the minors, J.A. K’d plenty of hitters with his plus changeup (9.3 K/9 during his minor league career, including 10.1 per nine with AAA Lehigh Valley in 2008). However, Happ also likes to work high in the zone with a fastball that sits roughly 88-91 MPH. Take a look at his Pitch F/X data: his fastball is straight as an arrow (1.8 inches of tailing action in on lefties), with 12.2 inches of vertical break. That above-the-belt approach didn’t cause that much damage in the minor leagues (0.7 HR/9), but Happ has surrendered 1.25 HR/9 during the course of his big league career. J.A. also doesn’t necessarily fit the “finesse lefty” profile, either, as he issued 3.5 BB/9 in the minors (3.52 BB/9 in the majors).

The purpose of this post certainly isn’t to knock Happ; he’s a perfectly useful fourth or fifth starter, and clearly a better alternative to the Kyle Kendrick’s and Park’s of the world. But, it’s probably a good idea not to get too enamored by his fast start as a starter. Heading into the 2009 season, Baseball America said the following about Happ (dubbed the 9th-best prospect in the system): “Happ lacks a standout pitch and doesn’t figure to get all those strikeouts on fastballs as easily in the majors as he did in Triple A…He projects as a fourth starter in the long term.”

That assessment still seems accurate to me. Happ can post a league-average K rate, while handing out a few too many free passes and homers to be more than a good back-of-the-rotation option. ZiPS forecasts a 4.93 FIP for Happ for the rest of the 2009 season. There’s nothing wrong with playing Happ in deeper leagues. Just don’t be totally surprised if some of those bloops evade gloves and the Houdini act with runners on base comes to an end.