According to research from Pizza Cutter, pitchers’ strikeout percentage per plate appearance (K/PA) stabilizes after they have faced 150 total batters. It just so happens that all five starting pitchers in the Cardinals’ rotation have recently surpassed this threshold, so I thought it would be fun to create a visual that pits their 2012 K/PA against career rates. The graph is below followed by some brief commentary (after the jump).
An increase in strikeouts is a welcome development for any starting pitcher, but I’m inclined to believe the few percentage points for Kyle Lohse and Jake Westbrook are nothing more than blips. After all, while they have technically struck out more than their usual share of batters, they are still well below the 19.2% league average rate.
In 2011, Jaime Garcia asserted himself by maintaining his strikeout rate while simultaneously reducing his walk rate, but we’ve seen the opposite in 2012 as his K/9 has dropped considerably and his BB/9 is slightly elevated. Together, it creates the worst K/BB ratio of his short career as a full-time starter. Jaime’s 4.09 ERA is likely a product of poor luck on balls in play (.342 BABIP). While that’s reflected in a much lower FIP (2.98), don’t let that reassure you too much because he’s benefited from an impossibly low 2.5% HR/FB (average is around 9.5%). After accounting for his good fortune on home runs allowed per fly ball, we see his actual results (in terms of ERA) aren’t too far off from what we would expect given a normalized rate (3.92 xFIP).
What isn’t to like about Lance Lynn? He leads the starters in ERA (1.81), FIP (2.87), has kept more than 50% of balls in play on the ground, and he throws the hardest (92.5 mph fastball). Oh yeah… and he has maintained a strikeout rate that is on par with that of his stellar 2011 performance out of the bullpen.
It’s been well documented (especially at VEB) that Adam Wainwright‘s peripherals have outshone his results (6.16 ERA), and that’s further illustrated here. While the graph suggests that he has struck out quite a few more batters compared to his career, his 2012 K-rate (23.4%) is the exact same percentage that he posted back in 2010. Don’t worry much about the high run total. Assuming Wainwright continues to strike out hitters at this rate and he gets some better luck on balls in play (.352 BABIP) and HR/FB (25%), the outcome should be drastically different. This is evidenced by his 2.93 xFIP which actually leads the rotation. There just isn’t much of a reason to be discouraged by Waino’s return from Tommy John surgery.