Dissecting Jeff Karstens: Can He Keep This Up?

Coming into the 2011 season, Pirates starter Jeff Karstens had 12 career wins with an ERA in the 5.00 range, and had never pitched more than 122 innings in any one major league season. He's not a big strikeout pitcher as his highest K rate in his major league and minor league career occurred way back in 2006 when he struck out just over 8 batters per nine innings. He also is not a big ground ball pitcher as he induced 42% of the balls in play last year in his 122.2 innings or work.

This season, he is surprising every fantasy owner, and probably coaches in Pittsburgh as well, because I don't think anyone saw this coming from Karstens. Thus far in 2011, Karstens is 6-4 with 2.65 ERA, 4.70 FIP and 3.78 xFIP, which says the future may bring some struggles for Karstens, but he will still be a serviceable starting pitcher on fantasy teams.

Or is he? More after the jump:

As stated before, Karstens is not a big strikeout pitcher, as he is striking out just 5.40 batters per nine and his walk rate is acceptable at 1.77/9 this season. He has slightly increased his K rate from last season from 5.28 to 5.40, and has reduced his walks from 1.98 to 1.77, so he is basically the same pitcher he was last season.

What stands out to me are his BABIP and his strand rate, or LOB% per Fangraphs. After allowing a .309 BABIP in 2010, he is getting very lucky this season, as his 2011 BABIP sits at just .238. That BABIP is not sustainable, especially for a pitcher who doesn't strike out many batters and relies on his defense.

After allowing strand rates (LOB%) of 62.5% in 2008, 66.1% in 2009 and 70.5% in 2010, Karstens strand rate this year has risen dramatically to 86.7%, which is extreme. To give you a better sense of how extreme that strand rate is, only 3 pitchers had strand rate above 80% in 2010 and their names were Cole Hamels, Roy Halladay and Tim Hudson. Karstens is not a Hamels or a Halladay, because one is the best pitcher in baseball last year (Halladay), and the other could be the best pitcher in baseball this year (Hamels). Hudson doesn't strike out many batters, like Karstens, but Hudson compensates by inducing more ground balls than almost any pitcher in baseball. Hudson led MLB with a 64.1% ground ball rate last year.

Speaking of balls in play, Karstens has reduced his line drive rate from 18.1% to 17.6%, and his fly ball rate from 39.9% to 37.7% thus far in 2011. He has also increased his ground balls from 42.0% to 44.7% this season as well, which is a good sign. What is not a good sign is his HR/FB rate, which has increased from 12.5% to 15.0% this year, and he is allowing 1.5 home runs every nine innings, which is slightly higher than his career rate of 1.38.

Karstens plate discipline stats haven't fluctuated much from 2010, with three exceptions. He is inducing slightly more swinging strikes 8.0% vs 7.5% in 2010, and allowing less contact on pitches in the zone- 88.9% vs 91.0% in 2010. But, he is throwing less first pitch strikes this season-61.4% vs 66.1% in 2010.

Given his extremely low BABIP and extremely high strand rate this season, combined with the fact that Karstens is not a big strikeout pitcher, indicates to me that Karstens is benefitting from some good luck this season.

What do Fake Team readers think?