At This Velocity: Five MLB Relievers Losing Fire on Their Heat

We crunched the numbers on five starting pitchers who have lost velocity on their fastballs since June of 2012. Bill Petti from fangraphs.com compiled a sizable list of starting and relief pitchers for his monthly Velocity Decline Trends for the month of June. We will now take a look at five relief pitchers who have lost velocity on their fastballs in that same time span as we try to explain and figure out how this loss of velocity might have an affect on their 2013 season.

Disclaimer: Usually when I analyze baseball data I tend to combine both “real baseball” and “fantasy baseball” perspectives interchangeably. All stats are good through July 9, 2013.

Common Ground: Despite losing at least one mph, all of these relievers are still posting fastballs at 92+ mph. Also, for the most part, these relievers have a reputation for being some of the best closers in the game right now–especially in fantasy baseball:

• It’s alarming to see Addison Reed already losing 2+ mph on his fastball despite being the youngest.
• Joe Nathan is the oldest reliever on this list and it’s amazing how he can still average 92.5 mph on his fastball despite undergoing Tommy John surgery in 2010.
• Chris Perez might be the worst closer of the bunch in terms of ERA and a terrible K/BB.
• We’ve mentioned before how Jason Grilli has helped not only the Pittsburgh Pirates, but also fantasy points leaguers alike.
• Jonathan Papelbon has four blown saves so far this year, but hasn’t blown a game since June 17.

Let’s take a look at their strikeout and skill statistics:

Common Ground: All pitchers can rack up the strikeouts although Perez and Papelbon have only posted average strikeout rates.

Pepelbon is the only pitcher on this list who is below K/9 league average among relief pitchers (average is 8.28 this season). Does that have something to do with a loss in velocity? It can’t be an issue with age because Grilli and Nathan are much older than Papelbon and are posting above average K/9. To his credit, he has posted an average strikeout rate of 21.7%. However, that is still the bottom figure among this group.

Not surprisingly, Perez’s terrible K/BB is a result of a really high walk rate. He also has the worst FIP in this group. If Perez had pitched enough innings in the first half of the season, he would actually own the eigth worst FIP among relievers, just ahead of teammate Vinnie Pestano and Chicago Cubs’ reliever, Hector Rondon.

League average FIP among relievers is 3.77 and Papelbon is close to hitting that mark. Just like Perez, Papelbon is above league average in HR/9 among relief pitchers.

Let’s take a look at how a decrease in velocity has affected their batted ball percentages:

Common Ground: All of these relievers are flyball pitchers–except Chris Perez, but he doesn’t induce enough ground balls to be an effective ground ball pitcher. The other four pitchers force enough flyballs where they don’t worry about giving up home runs. As a matter of fact, Reed, Nathan and Grilli have done a great job in forcing pop-ups. More than half of Reed’s flyballs are of the infield variety.

Papelbon continues to be a mystery. He forces enough flyballs, but has the highest HR/FB rate among the four flyball pitchers. I believe this is a combination of a drop in velocity and pitching in a small, home ballpark. Astonishingly enough, he’s the only pitcher on this list that is below league average in Line Drive%. Which would explain his BABIP and SIERA being below league average. But his SIERA might indicate that his luck might be running out. Low strikeout rate and has issues with the longball usually calls for a forecast of bad. But to his credit he has gotten the job done in the 9th inning since his last blown save in mid-June.

Grilli has posted a high number strikeouts and saves while maintaining a low walk rate should just indicate that Grilli is a totally, dominant closer. and he’s done all of this with a BABIP of .308. Part of it can be explained by his Line-Drive% being above league average, but he doesn’t give up many home runs and forces plenty of pop-ups. His SIERA indicates that he can actually pitch a lot better than he has shown so far–which is a scary notion at this point, but it’s possible, especially with a BABIP above .300. The same explanation can be used for Reed, but it doesn’t seem he will be as dominant as Grilli.

Finally, we look at these pitchers’ plate discipline:

I hate to keep beating on Perez (actually, I don’t), but his decreasing velocity along with a lack of control has affected how hitters react to his pitches. He’s the worst pitcher in this group, by a long shot, who doesn’t force “bad swings” as evident by his below league average SwingingStrike%. Hitters are just not swinging at many pitches against Perez. When they do, however, hitters are making solid contact at pitches that do make the strike zone. Even if they don’t make contact and just let their bats rest on their shoulders, Perez’s control is so bad, that hitters might settle for the free base.

Reed and Nathan are nearing league average in O-Swing%, but they’re still forcing SwingingStrike% above league average. Both, more noticeably Nathan, do a good job in getting ahead of hitters, early in the count.

Papelbon’s velocity drop might explain why hitters like swinging at his pitches in the strike zone as just like Perez, hitters make good contact at his strike zone pitches. He too can force Swinging Strikes, but the fact that hitters are making good contact on his strike zone pitches that he is clearly throwing less pitches in the strike zone (40.8%) because he knows that hitters are keeping up with pitches inside the zone. It looks like as long he forces hitters to swing outside the strike zone, he can continue to be an effective closer, but his other numbers indicate that he’s due for more struggles in the second half.

On the other hand, Grilli forces plenty of hitters to swing at his “bad pitches” outside the zone and have a hard time making contact with his pitches. Add to the fact that he has a BABIP above .300 and it looks like Grilli might be do for better numbers in the second half.

So it looks like the only pitcher struggling to cope with a drop in velocity is Papelbon. Perez is just having an awful time with control. The other three pitchers have done a great job in getting enough strikeouts, limiting their walks, showing good command of their pitches, and might pitch better in the second half–barring any injuries, mechanical issues, and mental breakdowns, of course.

Felipe Melecio

Felipe Melecio was the managing editor for the blog Pathological Hate. He believes that math is your friend and numbers can be fun, especially when it comes to baseball. Keep tabs on all his knee-jerk reactions on Twitter: Follow @pathological_h8 !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0],p=/^http:/.test(d.location)?'http':'https';if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=p+'://platform.twitter.com/widgets.js';fjs.parentNode.insertBefore(js,fjs);}}(document, 'script', 'twitter-wjs');

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