Petti: Velocity trends through May 2013

From SABR member Bill Petti at FanGraphs on June 10, 2013:

We are a little more than two months into the season, and that means it’s time to check on early season velocity trends. As I’ve mentioned before, declines in velocity are a less reliable signal in April and May than in June and July, but nevertheless large declines can still be a solid predictor that a pitcher’s velocity has in fact truly declined and will remain lower at season’s end. Almost 40% of pitchers that experience a decline in April — and almost 50% in May — will finish the season down at least 1 mph. And while the signal gets much stronger in July, 40% is still a pretty sizable number.

So let’s take a quick look at the major decliners from April and May.

The chart below shows those pitchers that lost at least 1 mph off of their four-seam fastball velocity relative to the same month a year ago*. I’ve also noted whether the pitcher experienced a similar drop two straight years. Each pitcher’s adjusted ERA and FIP for those months is also included.

Read the full article here:

Related link: Bill Petti will be a featured panelist at SABR 43 in Philadelphia; register today to join us!

Originally published: June 10, 2013. Last Updated: June 10, 2013.