I'll tell ya, American League hitters just aren't what they used to be.
Not this year, anyway. Very quietly, there's a pretty serious power outage going on in the Junior Circuit.
According to FanGraphs, the AL's Isolated Power (ISO)—basically slugging percentage without singles for a more accurate measure of power—at the start of Tuesday's action was .142. That's down from .149 in 2013. The AL has also gone from homering once every 33.3 at-bats to once every 37.5 at-bats.
And 2014 isn't just a down power year for the AL relative to 2013. It's on track to be the AL's worst power year of the 2000s:
|Year||AL AB/HR||AL ISO|
Yup, it's bad. Before our very eyes, AL power is going back to the stone age.
And no, you can't blame it on the pitchers.
Per Baseball-Reference.com, AL pitchers have only seen their ISO drop a single point from 2013. FanGraphs has the AL's non-pitcher ISO at .142. Since that's the same as the league's collective ISO, yeah, this is on the AL's hitters.
So what, exactly, is going on?
A couple of things, really, with the first and foremost being...
Strikeouts and Ground Balls Make it Pretty Hard to Hit for Power
Knowing this, it's actually commendable that the AL's strikeout rate is down this year...But only to a degree. American League hitters are striking out in 19.4 percent of their plate appearances, which is down just three points from last year's all-time high of 19.7 percent.
So yeah, the AL is still a high-strikeout environment. That's not a good thing for power. For to hit for power, one must first hit the ball.
What's even worse in 2014 is how AL hitters haven't been helping their chances of hitting for power when they have hit the ball.
FanGraphs has batted-ball data going back to 2002. And so far in 2014, AL hitters are working on their highest recorded ground-ball rate (GB%):
This is not good. For while ground balls have a solid chance of becoming hits, they don't go for extra-base hits nearly as often as line drives and home runs.
For some perspective, here's how the AL is doing on flies, liners and grounders in 2014 (via Baseball-Reference.com):
So all the strikeouts? Those are a whammy.
All the ground balls too? That's a double-whammy.
There are likely several explanations for all the ground balls, but one would seem to be based in pitch selection.
With a disclaimer that some pitches can be misclassified, the PITCHf/x data at FanGraphs says AL pitchers are throwing four-seam fastballs just 35.2 percent of the time. That's the lowest rate of the PITCHf/x ERA (since 2007), and notable gainers in usage have been two-seamers, splitters and cutters.
If true, that's significant.
As Harry Pavlidis pointed out in a 2011 The Hardball Times article, cutters have a higher ground-ball rate than four-seamers. Two-seamers/sinkers and splitters, meanwhile, have a much higher ground-ball rate than four-seamers.
In light of this, it's not a shocker that AL pitchers are currently working on their second-best recorded ground-ball rate.
And it's not just them. As I recently noted, National League pitchers are also racking up ground balls these days. Since AL hitters now have to face NL pitchers on a regular basis, the assault on their power is coming from all sides.
If you want the big explanation for the AL's power outage in 2014, there it is. Strikeouts and ground balls, man. Strikeouts and ground balls.
But also not helping is how...
Some AL Power-Hitting Havens Aren't Acting Like Power-Hitting Havens
First off: No, American League parks as a group actually aren't suppressing much power.
Not if the home run park factors at ESPN.com are to be believed, anyway. With an average home run factor of 1.057, AL parks have actually been largely friendly to home run hitters in 2014.
What's odd, however, is how some parks are playing against type.
One is Oriole Park at Camden Yards, the close-quartered home venue of the Baltimore Orioles. ESPN's park factors had it as a top-five home run haven in both 2012 and 2013. So far in 2014, however, OPACY has been MLB's 27th-friendliest home run haven.
U.S. Cellular Field, home of the Chicago White Sox, is another one. ESPN's park factors had it as a top-seven home run haven in 2011, 2012 and 2013, but it ranks 19th thus far in 2014.
Then there are the two Texas parks. Minute Maid Park has seen it's home run factor drop .192 points from 2013, the third-largest drop in the AL after Baltimore and Chicago. Glove Life Park in Arlington, meanwhile, is continuing a downward trend as a power haven that began last year, as power production in Arlington has been at its lowest in the last two seasons.
The X-factor here is the weather. We haven't gotten deep into the season's warmer months just yet. Once we do, perhaps power fortunes at these parks—U.S. Cellular Field in particular, methinks—will be turned around and the AL will get a boost in power.
In the meantime, however, it's not just some AL parks that are acting differently. Also happening is how...
Players Have Changed, Too
There are some pretty great power seasons happening in the American League. Jose Abreu, Nelson Cruz and Edwin Encarnacion are leading the way, as each has at least 15 homers and an ISO over .300.
In all, there are 15 qualified American Leaguers with an ISO of at least .200. Since a .200 ISO is really good and 15 is not a small number, this is good stuff.
It's just not quite as good as 2013, when there were 17 qualified players in the .200 ISO Club.
One reason the .200 ISO Club has fewer members in 2014 is because six of last year's members—one of whom is a newly minted $240 million man—have seen their ISO drop below the .200 threshold:
|Player||2013 ISO||2014 ISO|
Not mentioned here are Chris Davis and Miguel Cabrera. The latter's 2014 ISO is 76 points off his final 2013 figure, and the former's 2014 ISO is 120 points off his final 2013 figure. Injuries have played a part in this, because injuries are mean and stupid like that.
But there's also how the American League hasn't gotten a power boost from former National Leaguers the way the National League has gotten a power boost from former American Leaguers.
There are five guys who played entirely or mainly in the AL in 2013—Mike Morse, Seth Smith, Mark Reynolds, Justin Morneau and Jhonny Peralta—in the NL's .200 ISO Club. Conversely, there are no former NL'ers in the AL's .200 ISO Club.
All told, here are your ingredients for the American League's power outage in 2014: lots of strikeouts, lots of ground balls, a couple parks playing against type and a relative dearth of elite power hitters.
Maybe it won't last. Heck, there's a decent chance it won't. There's a lot of season left, and it bodes well for the AL that we're just now getting into the months where the ball tends to have a little extra carry.
But if ever there was a blueprint for how to knock the AL's power down a peg, we're seeing it in 2014.
All stats are current as of the start of play on Tuesday, May 27.
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