When Yankeeist last looked at Alex   Rodriguez’s declining  power numbers, I (and several others) came to the rather obvious conclusion that his  paltry 8.3% HR/FB rate would soon escalate. Alex’s five home runs since  that point in time have indeed bumped his rate up, but it’s only sitting  at 12.1%, still well below his 23.3% career percentage.
A-Rod  has eight home runs on the season to date; the lowest number through 58  games of his career and only the second time he has accumulated less  than 10 this deep into a season — in 1997, he had nine through 58 games  with the Mariners. So what’s going on with Alex?
The below table  shows historical batted ball numbers for A-Rod, his  year-to-date home  run totals (in this case, through the first 58 games  of each season),  and his season home run totals (all data c/o Fangraphs and B-Ref):

Despite  five big flies, Alex’s fly ball percentage is down from when I last looked at the numbers on May 10.  Accordingly, his line drive percentage is also down, to 17.9% (though  this is barely off his career rate) and his ground ball percentage is  up, to 46.2% (pretty well above his 42% career rate).
As you can  see, Alex has never had a Fly Ball % this low in a full season for as  long as Fangraphs has recorded this data, which partially explains why  his HR/FB rate has only risen by 3.8 points — he’s just not hitting as  many fly balls as he usually does. Assuming his Fly Ball % normalizes to  his career rate, we should see a corresponding uptick in the HR/FB  percentage.
Here are the different pitch types A-Rod has seen:

Pitchers  are obviously aware that A-Rod isn’t hurting the baseball as much as he  usually does, as they are challenging him with more fastballs than ever  before. Correspondingly he’s seeing less of every other pitch type  since May 10, with the exception of a slight increase in changeups and  split-fingered fastballs. Looks like the book on ‘Rod remains challenging him with the heater, which means he’s going to have to make  some adjustments to his approach, as there’s no reason Alex shouldn’t be  able to adequately handle a steady diet of fastballs.
And here are his  swing percentages:

Since I last conducted this analysis, Alex is swinging at even more pitches  out of the zone (25.8%) but making less contact with them (60.1%), and  also swinging at more pitches in the zone (65.7%) and making less  contact with those as well (91.8%, down from a crazy high of 97.3%). His  overall contact percentage is 81.4%, still a good deal higher than his  career rate of 75.5%.
It would appear Alex’s biggest problem is  that he’s trying to make too many things happen with the bat right now  — swinging at pitches out of the zone has contributed to an  above-average (for Alex) contact rate, which is resulting in more balls  being pounded into the ground than lofted into the air (hence the  career-low Fly Ball %).
Alex has also eschewed his trademark  patience during the past month. He had 19 walks through 31 games, but  has only walked seven times since then over his last 27 games. His OBP  has dropped from .381 on May 10 to .360.
While A-Rod still has time to improve his numbers, and ZIPS ROS projection has him hitting a robust .284/.378/.512, .392 wOBA and 18 home runs the rest of the way, that would still only get A-Rod to a full season line of .285/.371/.499 with a .381 wOBA and 26 bombs, which would mark his lowest SLG, home run total and wOBA since 1997.
Basically, A-Rod needs  to stop swinging at bad pitches, take a few more walks and show pitchers  he can still punish the fastball if we’re going to see significant  improvements in the Fly Ball % and HR/FB rate and get his numbers anywhere near his career line of .304/.389/.573. I realize that’s a rather obvious conclusion that probably didn’t require a comprehensive statistical analysis, but it’s nice to see that the numbers support it.
Larry Koestler eats, drinks, sleeps  and breathes the Yankees at his blog, Yankeeist.