Tonight, Stephen Strasburg returned from Tommy John surgery to make his season debut for the Nationals. Here is a look at his Pitch FX speeds from tonight compared to one of his starts from last season.
It can be seen that his average fastball speeds are about 1 MPH slower tonight than last year. The change is nothing to worry about, especially for a pitcher that has a fastball that averages 97 MPH.
The most noticeable change was a “new” off-speed pitch. His changeup was not breaking down as much today. This season, the average horizontal break was -9.4” and the vertical break was 5.3”. Last season the values were -7.7″ for the horizontal break and 0.0″ for the vertical break. Also, the changeup is closer to the same plain as his fastball. This difference can be seen in the following two images (thanks to Brooksbaseball.net):
Note: It can also be seen that his fastballs are not drop as much as they did last season.
The difference in the changeup is due to a different spin axis on the ball has seen from these two graphs.
From the few cut-ins I saw of the game, there was no mention of a new changeup grip. It has a new spin and break compared to the one he threw last season.
Strasburg is throwing a bit slower this season than last. Also, he looks to have added a changeup that breaks down less. As a whole, he seems back in form and the results tonight seemed to speak for themselves.
Jeff, one of the authors of the fantasy baseball guide,The Process, writes for RotoGraphs, The Hardball Times, Rotowire, Baseball America, and BaseballHQ. He has been nominated for two SABR Analytics Research Award for Contemporary Analysis and won it in 2013 in tandem with Bill Petti. He has won three FSWA Awards including on for his MASH series. In his first two seasons in Tout Wars, he's won the H2H league and mixed auction league. Follow him on Twitter @jeffwzimmerman.