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Edwin Jackson Is In Love With His Slider

There is an old adage when it comes to pitching that you have got to establish your fastball first and foremost. The other pitches are deemed ‘secondary pitches’ for a reason.” Apparently, Edwin Jackson has little use for this piece of baseball wisdom, as 2011 has seen him throw his slider more than ever in his career. Last night’s World Series Game 4 was no exception, as Jackson offered the pitch 46 times in his 109 pitches (42.2%) – nearly identical to his Pitch F/X slider percentage of 42.3 in 2011. Jackson’s reliance on the slider last night led to his seven walks – so, despite that he allowed just three hits, Tony LaRussa was forced to relieve him with Mitchell Boggs in the 6th inning. Boggs will not likely be available tonight in the pivotal Game 5 as he threw 29 pitches – his third highest total since August 27th.

Jackon’s slider usage is curious. A picther who has never been labeled a “command guy”, Jackson is one of the hardest throwers in baseball, with his fastball checking in at 94.7 MPH in 2011. For someone who has struggled with his command, Jackson has increasingly utilized a pitch that can generate sharp movement on both planes. This season, Jackson offered the slider in high percentages with two strikes, and regardless of the number of balls. When he was ahead in the count at 0-2 and 1-2, he offered the pitch 56% and 54% of the time, respectively. With the count even or full, those percentages dropped to just 53 and 49. For contrast, Clayton Kershaw, who produced the gold standard for slider usage in 2011, offered his slider in 3-2 counts 34% of the time. Kershaw’s wSL came in at 22.8 in 2011, while Jackson’s checked in at just 1.8 with 30 starting pitchers in MLB generating more value from their slider than Jackson, and just two – Ervin Santana and Bud Norris – offering it at a higher rate.

Jackson’s dependance on his slider has created another problem in his game – the running game. This season baserunners were 22 for 23 in SB/AT on Jackson. Despite the fact that the pitch is moving to the arm side of the catcher, the movement and slower speed of the pitch makes for a difficult transfer and throw. Last evening, he was fortunate that Yadier Molina picked his slider in the dirt and threw behind Ian Kinsler to end the 2nd inning.

In 2011, Jackson did have success in getting batters to chase – 32.9% of batter swings were on pitches out of the strike zone. It would behoove the Cardinals and Jackson, if he does start again this series, to not rely on getting the Rangers to chase. As we saw last night, the Rangers employed a good approach – get into deep counts and take the free passes by watching Jackson’s favorite pitch slide out of the strike zone.

Jackson does deserve credit for trying a new approach in his free-agency year. Most pitchers with command issues likely would not decide to start throwing their slider more than ever in their walk year, and Jackson had one of his better campaigns in 2011. He is in the top tier of free-agent starting pitchers this off-season and his final effort in 2011 may be worth several million dollars – money that will be earned or lost on his slider.