Is Arod’s Bat Speed Really Declining?

It seems like just yesterday that we discussed how Derek Jeter was too old to hit fastballs, and I don’t think that premature assessment could have been any more inaccurate. While the Captain has gone about dismissing these rumors with some unthinkable numbers over the last year, the pessimists have turned their eye to the elderly Alex Rodriguez. According to more sources than I care to mention, the youthful velocity of today’s budding pitchers is too fast for Rodriguez’ hulking yet sluggish bat. Like Derek Jeter was too old for a young man’s game last year, the spotlight of ageism is now on Alex Rodriguez and a lack of bat speed. My eyes are far less trained than that of your professional scout, but when I hear or see on-field behavior, I usually turn to the numbers. In the case of Alex Rodriguez v. The Fastball, the data is certainly available to rule on these cynical assumptions.

For one, we can find the whiff rate on four-seam fastballs from the beginning of the PITCHf/x era (2007) to 2010, and his 2011 season, where this myth began, until today. From 2007-2010, Rodriguez took 2176 four-seamers, swung at 44.0% of them, fouled off 18.5%, put 18.6% in play, and whiffed 6.9%. From 2011 to today, with 857 four-seamer pitches to work with, the third baseman has a very similar 42.7% swing rate, fouled off 16.9%, put 18.1% in play, and whiffed 7.7% of the time. Although the whiff numbers increased by 0.8%, the difference is hardly significant enough to attribute to decreased bat speed. So clearly he isn’t whiffing at fastballs at a ridiculous rate, but perhaps he isn’t making good contact with hard fastball.

In the chart above, all of Alex Rodriguez’ hits off fastballs have been listed. Of his 38 hits in 2012, 22 have been off fastballs, 57.9%. The hardest fastball he hit was no slug, a 97 mph fastball that the slugger crushed for a homerun off Justin Verlander. The average fastball velocity this year is currently at 91.6 mph, but Arod has seen fastballs at an average of 92.8 mph, which matches up perfectly to the 92.9 mph average fastball he’s hit. So for those that say Rodriguez can only hit slow fastballs, he’s shown no tendency to hit slower or faster pitches.

As for why it would appear that Rodriguez is whiffing on fastballs too often, I have my own theory. Although I’m weary of the automatic pitch identification Gameday’s algorithm assigns to pitch types, there is definitely something that sticks out. 2012 has been the year of the sinker for many pitchers, and the pitch type has increased overall from 10.4% use in 2011, to 13.5%. For Arod, the selection has nearly doubled from 9.2% in 2011 to 17.7% in 2012. A sinker from a right handed pitcher will move in on a right handed hitter, and if the location is in to jam a batter, the hitter will often whiff due to the movement. Doubling the sinker to Rodriguez has increased his groundball rate from 48.6%, to 52.0%, but has also made him look helpless on the dangerous jamming pitch in. Some might think he’s being beat by velocity, but I’d bet movement is playing a bigger factor.

The stats haven’t been MVP-worthy this year, but I have faith that the homeruns will come. Even without huge power numbers, Rodriguez still has significant value at third base hitting the way he is. Now that Rodriguez is on a hot .375/.455/.458 streak in May, the critics will have to wait a few weeks for a slump to call him old again. With whiff rates showing no significant increase, and his hit fastballs showing no velocity decrease, there is no reason to worry about Rodriguez’ bat slowing down yet.

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