Time to Worry Over Chris Carpenter?

Chris Carpenter of the St. Louis Cardinals has made thirteen starts since the last day of August last year. During that span, his record is 2-6 with 40 earned runs in 82.2 innings of work. That works out to a 4.35 ERA over that span. So far this year, he is 0-2 with an ERA of 4.19. Worse yet, Carpenter had been downright stingy with home runs allowed in 2009 and 2010 but has given up six already this season in 43 innings of work. Should we be worried about this 36 year old pitcher?

Maybe. Or maybe it's time in his career when he can still help the Cardinals and not be the dominant pitcher he was in 2009 or for the first three quarters of the 2010 season. Perhaps it is time to lower expectations a bit. Carpenter did make 35 starts last year with a total of 235 innings pitched. That's a lot for someone who was 35 years old and just two years removed from major injury problems that cost him two years of service in 2007 and 2008. Perhaps his tank got emptied a bit last year towards the end. He certainly seemed to wear down similar to what Tim Hudson, a similar aged pitcher with similar skills, did in Atlanta.

But there are other signs that he's just not in sync yet and has a chance to still be the kind of pitcher the Cardinals expect from their ace. His velocity is a tick below where it was in 2009, but it's slightly above his 2010 averages. Pitch/FX also shows with his heat maps that he is throwing with the same sort of patterns this year as in 2010 and 2009. The only real difference in his charts is a slight dip in horizontal movement in his fastball. His release points look consistent as always.

Part of Carpenter's strategy was to get easy outs by inducing right-handed batters to pull the ball and left-handed batters to hit the ball weakly the other way. In 2009 and 2010, his OPS against in both those situations were very low. Perhaps with less movement on his fastball or perhaps because batters have adjusted, his OPS against in those two situations is dramatically higher. Carpenter may have to make slight adjustments to counter what hitters are doing in those situations.

Carpenter has given up a much higher line drive percentage than in his past. When a stat like that is way off his career norms, you expect it to come around to what he usually does. You would also expect his rate of homers to fly balls come down to his career average over the course of the season. His current homer to fly ball percentage is extreme at 16.2 percent. That's way over his career average of 10.6 percent. In fact, the only year he came close to that high a percentage was 15.5 percent way back in 2004.

One other thing of note: Carpenter throws more change ups than he did in 2009. In 2009, only 1.6 percent of his pitches were change ups. That figure increased to 3.7 percent last year and is at 4.2 percent this year. The pitch seems to be his least effective pitch and it looks like he is getting hurt with the change up this year. It might be a good idea for him to throw less of those going forward.

The bottom line from this Fan's amateur sleuthing through his numbers seems to be that Carpenter hasn't lost his stuff. His velocity is where it was last year. He may need to figure out why there is less movement on his fastball, which may be just a slight mechanical adjustment. His K/9 and BB/9 rates are just fine and consistent with his career. Carpenter just needs to get back to his career norm for homer to fly ball ratio and line drive percentage and he'll be fine. The prediction here is that once the weather improves and he gets into a regular rhythm, he will still have a good season for the Cardinals as long as he stays healthy. No real worries here.