How Long Will Zack Greinke's Great Start Last?

Breaking news: Zach Greinke is really good. We've all watched the scoreless innings streak and the 5-0 start, but seriously Greinke is really, really good. He has given up just two earned runs (both last night) and three runs overall in five starts this season. More impressively is he has given up just 24 hits (no home runs) and walked eight batters while striking out more batters (44) than innings pitched (36). Immediately, my brain says "well this is a nice run for a nice kid, but this is unsustainable." But is it really?

Ok, so maybe a 0.50 ERA and a 1.48 FIP are a bit unsustainable over the course of 35 starts and 200+ innings, but overall I don't see much "fluke" written on Greinke's success. His BABIP of .294 is slightly down from his career mark of .315 and his line drive, ground ball and fly ball percentages are all within six percent of career averages.

One thing you'll notice right way is his ground balls are up and fly balls are down. This change could be due to a slight change in pitch selection. His fast ball usage is down from a career 61.4% to 57.0 and his slider/curveball usage are up around three percent on each.

Also up is the percent of swing strikes that Greinke is getting. After last night's game, his SwStr% of 12.2% is second in the best in the American League behind Scott Richmond, who has an incredible SwStr% of 13.1. With the increase in swinging strikes has come an increase in overall strikeouts. As I mentioned above, he has more strikeouts than innings pitched giving him a K/9 of 11.00. With more strikeouts have come fewer walks and Greinke is surrendering just two free pass per nine innings. Overall, his K/BB rate of 5.50 ranks third best in the league.

While the peripheral stats tell us the success is real, we are still dealing with a small sample size. Assuming he stays healthy and makes 35 starts, we are just 1/7 of the way done. However, in Greinke's case which will be chronicled by Sports Illustrated next week, you can't help but root for him. Dayton Moore did make a few head scratching decisions this off-season (Kyle Farnsworth, Mike Jacobs), but signing Zack Greinke to an extension was definitely not one of those moves.