Analyzing John Lackey’s new slider

For every pitcher, elbow injuries can threaten your career. Tommy John surgery has come a long way since the first procedure, but we still hear about the horror stories of what can happen when the surgery doesn’t work. There’s the tale of former Royals’ uberprospect John Lamb who lost all effectiveness, then we have Daniel Hudson who re-tore his UCL after 12 months of rehab, and the stories go on. John Lackey naturally had concern about going under the knife after the 2011 season, but he was also aware it would be hard for him to do worse than his 6.41 ERA on the year. But Lackey shows a different kind of return from surgery, by regaining his confidence and pitching like he’s back in his mid 20s. And a large reason for his success has been the faulty elbow.

When Lackey came to the Red Sox organization in 2010, they put a large emphasis on learning a cutter. The fascination of the pitch was warranted, as the cutter was becoming a sort of miracle pitch. Lackey started throwing the cutter over 40% of the time after never throwing one in his professional career, and dropped his four seam usage down from 51.1% in 2009 to only 15.2% in 2010-11. But the ramped up use of the pitch didn’t lead to more success, or even the same level of success that brought him his $82.5M contract. His strikeout rate plummeted, walk rate soared and his ERA reached career worst marks. It all lead up to his eventual Tommy John surgery, with a return date set for 2013.

There’s some concern in the baseball industry that increasing cutter use can lead to multiple issues, such as velocity loss and injury. Implying causation from correlation is risky business, and Lackey’s injury may or may not be because of his cutter, but it’s impossible to overlook. To further fuel the fire on the idea, Lackey stopped throwing the same cutter when he came back from surgery. He now throws a hybrid slider-cutter, which gets similar but unique movement from his old slider and cutter.

Here are gifs of Lackey throwing both his slider and cutter pre-surgery in 2011:

Lackey’s slider

Lackey’s cutter

You can easily tell the difference between the tight spin of the cutter and the longer, loopy break on the slider. Now take a look at his new pitch that he’s throwing post-surgery:

Lackey’s new slider

The break is much different from his other pitches, by turning downwards sharply at the end. This pitch has been huge for him, throwing it 27.2% of the time. He’s enticing hitters to chase the pitch 50.7% of the time, which is helping lead to his 25.2% swinging strike rate, tops in the league. Not only is he getting more strikeouts (21.6%), but Lackey is busting platoon splits that he’s struggled with most of his career. His slider got whacked fora .301 average by lefties before his procedure, and the new slider has it down to .233 in 2013 and only .150 so far this year. He’s pitching to the same success he had earlier in his career, with a strong 3.58 ERA and 3.28 FIP. It’s clear that Lackey’s new pitch is not only being used effectively, but is helping save his career. Even though he’s 35, he’s as effective as ever.