After CC Sabathia's first start of the regular season, the lefty's four-seam and sinker velocity were major narratives following a worrisome start. He's followed that up with three Sabathia-esque starts, where he was either dominant, or he was able to give the team length and a chance to win. Altogether, he's pitched 23.0 innings in his last three outings, giving up 4 earned runs, 4 walks, 19 strike outs, and 1 home run. Batters are hitting just .217/.250/.301 off of him, but that doesn't mean he fixed his velocity. As I pointed out earlier in the month, Sabathia's initial struggles on opening day were due to control, and not his lack of velocity. Despite offseason elbow surgery, the southpaw showed tremendous movement on all of his pitches on opening day, a much more important factor following such a procedure. Since then, Sabathia's movement has continued to impress, but his low velocity has remained.
He's thrown 426 pitches this year, each of them plotted in the graph above. There was some expectation that Sabathia's velocity would increase as he was stretched out and developed strength in April, but so far he's shown no signs of improvement. While his results have been successful, this four-seam speed is at an unprecedented low in his career. PITCHf/x has the ace's four-seam velocity sitting at 93.9 mph in 2011, and falling to 92.4 mph in 2012. Over his last four games, the average velocity on both his fastballs are illustrated in the chart below.
|Date||Park||FF Velo||SI Velo|
Keep in mind that we're only 28.0 innings into Sabathia's 2013 season, but as the innings add up, this starts to look like something significant to watch. As we enter May and June, a pitcher's velocity should reach its peak, and if Sabathia is still showing diminished speed, we'll have to start questioning both his health and his weight loss.
For what it's worth, three of the games he's pitched have been in Yankee Stadium. Overall, the PITCHf/x cameras in the Bronx have been slightly less friendly than other stadiums, averaging .13 mph less on four-seam fastballs based on pitcher's average four-seam velocity. This could be due to the cold weather, but there's a chance that the initial readings from the cameras have been slightly off in calibration.