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:
|Pitcher||Year-Month||2013 Velocity||2012 Velocity||2011 Velocity||2012-2011||2013-2012||2YR Decline?||ERA-||FIP-|
For the most part the list includes pitchers that were in the same role each year, but there are a few that switched roles — for example, Alexi Ogando has returned to the rotation this spring after pitching exclusively out of the bullpen last year. Rather than filter them out I thought I would leave them in for folks, if for no other reason than to see exactly what the impact of switching roles has been on velocity for specific pitchers.
(Side note–Ogando was placed on the DL with shoulder inflammation, retroactive to June 6.)
A number of interesting high-profile pitchers made the list in April (Roy Halladay would have been included, where it not for the fact that he is a sinker/cutter heavy pitcher), including the much discussed CC Sabathia. I wrote about Sabathia back in April and, while his performance and velocity have picked up since the early part of the season he is still almost 2 mph off his pace from last May. Of course, he was throwing .6 mph slower last May compared to May of 2011, so at this point I’d say we can more confidently say that the early velocity loss wasn’t just the result of his off-season elbow surgery.
The Rays’ David Price suffered declines in both April and May. Price was diagnosed with a strained left triceps and has since been placed on the disabled list. Prior to landing on the DL, Price was having a pretty bad season, posting a 134 ERA- and a 105 FIP. And while a FIP five percent worse than league average isn’t terrible, it’s a big disappointment when you are Price.
The Angels’ Tommy Hanson earns the distinction of the being the only pitcher on this list that both declined in April and May, but also did so in both month’s for the second consecutive year. The put it bluntly, Hanson is just bleeding velocity at this point. Despite an adjusted ERA that was 11% better than the league in April Hanson’s performance has taken a decidedly negative turn in May, with both his adjusted ERA and FIP ballooning. With a strikeout rate now down below 13% I hate to imagine what the rest of the season may hold for the 26-year-old.
Jordan Walden, who the Angels flipped for Hanson this past off-season, also appears on this list having lost velocity in both April and May. Walden has managed to post an impressive adjusted FIP of 36, however he gave up five runs in 1 1/3 innings over a three game stretch in May that pushed his adjusted ERA almost to average levels. Walden was placed on the disabled list after that three-game stretch with shoulder inflammation. Since returning, Walden’s fastball has seen better life, averaging closer to 96 mph, but still below 2012 levels. With relievers, their performance tends to fluctuate in greater sync with their velocity, so it’s definitely a situation worth monitoring.
Remember, pitchers that are down at least 1 mph in April compared to the previous April are over four times more likely to finish the year down at least a full 1mph. That likelihood jumps to almost eight when we look at May declines. Velocity doesn’t determine pitcher effectiveness, but it certainly plays a significant role. Pitchers can certainly adjust, but there’s never a guarantee that they’ll adjust effectively.
*Minimum of 40 four-seam fastballs thrown each month/year
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.