As some of you might remember from previous articles, velocity trends in July provide the strongest signal in terms of whether a pitcher is likely to experience “true” velocity loss over the course of a full season.
Yes, I know, we are more than halfway through August. However, between work, vacation, and Saber Seminar (which, if you didn’t attend you really missed out. You can still purchase posters and t-shirts, so get on that. It’s for a good cause) I’ve struggled to sit down and run the numbers. Better late than never.
Again, for reference, the table below breaks out the percent of pitchers who experience at least a 1 mph drop in their four-seam fastball velocity in a month relative to that same month a year ago and who also went on to finish the season down a full 1 mph. It also shows the relative risk and odds ratios for each month — meaning, the increased likelihood (or odds) that a pitcher will experience a true velocity loss at season’s end when compared to those pitchers that didn’t lose 1 mph in that month.
|Month||1 mph Drop||No 1 mph Drop||Relative Risk||Odds Ratios|
So while the overall rate of velocity loss based on a loss in June and July look pretty even, the relative risk and odds ratios increase by a solid amount in July.
Here is your list of pitchers that lost at least 1 mph in July of 2013 compared to last July, sorted by largest decline:
As before, the 2-Year Decline column notes if this pitcher suffered the same kind of decline the previous year (so, July 2012 compared to June 2011). I’ve also listed those pitchers where I had data on their velocity trends from June 2012 to June 2013, with negative values representing a velocity loss during last month.
We want as much context as possible when trying to read the tea leaves of velocity. To that end, I created a list of pitchers that threw at least one four-seam fastball in the month of July. This list then includes the pitcher’s month-to-month velocity trend during the 2013 season. You will also see a pitcher’s overall velocity change since April of this season.
So, let’s talk about Matt Moore.
Last month I noted that Moore’s velocity appeared down and headed for a real velocity loss based on his June over June decline. Turns out, Moore’s elbow started barking, and the Rays placed him on the 15-day disabled list. Moore was down 2.2 mph in June and 2 mph in July, relative to last season. Moore actually lost a bit of velocity between April and June of this season (-.3 mph), but experienced a decent recovery through the end of July (+.4 mph). So while he threw harder in July he still was way off his pace from last year.
Moore still managed an average velocity of 92.7 in July, which is pretty good for a left hander. However, as a 23 year-old, Moore’s fastball averaged 94 mph last year. If he continues at his current pace this year he could finish with an average velocity around 92.5 mph. That 1.5 mph drop increases his odds of experiencing further decline next year and would be below average (not in a good way) for a pitcher of his age. (Starting pitchers lose, on average, only about .2 mph between age 23-24.) The slightly good news for Moore? 24 year-olds have the second highest rate for velocity recovery the season after a decline. On average, those that regain velocity get back about .9 mph. However, only two out of fourteen pitchers regained velocity, and the average velocity loss for the remainder of those 24 year-olds was -1.7 mph.
Maybe Moore’s velocity loss can be attributed to an injury that can be treated without long term effects. If that’s the case, then there is less to be concerned about. At this point, we don’t have much more than “elbow soreness”. And elbow soreness is never a phrase you want to see attached to a young, front line starter.
Bill leads Predictive Modeling and Data Science consulting at Gallup. In his free time, he writes for The Hardball Times, speaks about baseball research and analytics, has consulted for a Major League Baseball team, and has appeared on MLB Network's Clubhouse Confidential as well as several MLB-produced documentaries. He is also the creator of the baseballr package for the R programming language. Along with Jeff Zimmerman, he won the 2013 SABR Analytics Research Award for Contemporary Analysis. Follow him on Twitter @BillPetti.