Adam Wainwright’s strikeout rates keep increasing. In over 400 innings in AA and AAA during his age 21-23 seasons, his strikeout rate was 7.8 per nine innings. When he was elevated to the majors in 2006 as a relief pitcher his strikeout rate took an expected jump to 8.64 K/9. At the time he was throwing his curveball 25.9% of his pitches. A return to starting the following year led to a decrease in both his curveball use (18.6% in 2007 and 17.9% in 2008) and his strikeout rate (6.06 K/9 in 2007 and 6.20 K/9 in 2008).
In 2009, Wainwright made a change in his pitch selection, reverting back to the curveball percentages from his bullpen tenure. The increase in curveball use (24.0% in 2009) increased his strikeouts per nine to 8.19 and turned him from an above-average pitcher (3.90 and 3.78 FIP in 2007 and 2008, respectively) to a Cy Young contender (3.11 FIP). The increased use of the curveball in 2009 also increased its effectiveness, doubling to 2.71 wCB/C. The effectiveness on his slider tripled. Unfortunately, his fastball decreased in effectiveness, going from essentially average to -.75 wFB/C.
In 2010, Wainwright has taken his curveball use to another level, increasing to 28.5% of his pitches and his strikeout rate to 8.26 K/9 and lowering his FIP to 2.86. He has not sacrificed control, lowering his walk rate to 2.21 BB/9. His curveball and slider, which may be more of a cutter, have been slightly less effective, but still very useful pitches. The significant change has occurred in the effectiveness of his fastball. Wainwright has decreased the number of fastballs thrown to a career low 46.5% of pitches. With this decrease has come a drastic increase in the effectiveness of the fastball without changing the velocity, moving to 1.00 wFB/C from last year’s total of -0.75 wFB/C.
Also of note, increasing his strikeouts has not affected his efficiency, with 15.7 P/IP in 2007, 14.8 P/IP in 2008, 15.5 P/IP in 2009 and a career low 14.6 P/IP in 2010.
Wainwright has remained effective this season throwing the third highest percentage of curveballs of any pitcher. (Only Wandy Rodriguez and Gio Gonzalez have thrown a greater percentage of curveballs this year.) When you have the curve he has, you can’t blame him. The consequence, whether inteneded or not, is a sea change in the effectiveness of his fastball. Another Cy Young-caliber season at a bargain price for the Cardinals.