Aaron Harang and Dustin Moseley, two free-agent pitchers the Padres signed during the offseason, have exceeded expectations for the first month of San Diego's 2011 campaign. The club struggled during the month of April, but the blame can be put squarely on the struggling lineup.
I have been more surprised with Moseley's success, but Harang and Moseley have pitched well taking into account the PETCO Park effects. It is also worth noting that the Padres have the second best UZR rating from 2010 to 2011, and while it is a small sample size it is an indicator that the Padres have an above average team defensively.
Harang has pitched to a 3.90 ERA and compiled a 4-1 record during the month of April. Obviously PETCO Park has a great effect on a pitcher's ERA, but Harang's xFIP of 3.77 (park adjusted) is lower than his ERA. He has improved his control, lowering his BB/9 from 3.06 to 2.40. Harang has improved his strikeout totals slightly from 6.61 to 6.90 K/9, but his swinging strike percentage has remained the same as 2010.
Harang has not benefited from a significant drop in BABIP, the .284 average is only slightly below the 2010 average of .290. While Harang is still a dominant fly-ball pitcher (43.8 percent this season), he has dropped his line-drive rate from 22 percent to 19 percent and increased his infield fly-ball rate from 7.8 percent to 17.9 percent. Harang's increased usage and downward movement of his best pitch, his slider, could be an explanation for his recent success.
Moseley had a strange month of April, getting very little run support and posting a 1-3 record with a 1.63 ERA. Even with that luck, Moseley's ERA was heavily influenced by a .236 BABIP, 83.3 percent strand rate and a 6.1 percent HR/FB ratio. He has pitched to a xFIP of 3.85, a number significantly greater but still below the league average.
Moseley's strikeout numbers are lower than ever at 3.72 K/9, and his swinging strike percentage is similar to last season. However, Moseley has made his own adjustments that have allowed him to be more successful. He has improved his walk rate from 3.72 to 2.09 BB/9, and he is currently inducing ground balls at a 57.4 percent ground-ball rate. Moseley's approach hasn't changed much; he has thrown a similar amount of fastballs, but he has thrown more cutters while limiting his change-up usage. (His curveball has been his most successful pitch.)
Keeping the ball out of the air benefits any pitcher, especially a pitcher who makes half of his starts at the best pitcher's park in all of baseball. Yet, Moseley has only made two of his six starts at PETCO and he has given up both of his home runs in San Diego.
PETCO Park and the Padres defensive squad are somewhat responsible for the recent strong performances of Harang and Moseley, but both pitchers deserve credit for making necessary adjustments. Harang should pitch to a similar ERA for the rest of the season, but Moseley's numbers should come back to earth soon. His strand rate is unsustainable, but the Padres defense along with a favorable ground-ball percentage should keep his ERA close to 4.00.