Mauer and the fastball

Baseball analysts league-wide, attempting to do what they are paid to do, are throwing in their two cents trying to explain Joe Mauer's sudden home run capabilities and an .845 slugging percentage. 

 

FSNorth's Ron Coomer told MinnPost's Pat Borzi that the power explosion has to do Mauer correcting a "weak-side drift" in his swing - that his front hip had the tendency to move forward right before swinging.  This correction has allowed Mauer to have a more balanced and loaded stride, generating additional power in his swings.  On another recent broadcast, FSNorth's other analyst Roy Smalley noted that Mauer's swing has a definite shoulder drop which is leading to more lift on the ball, hence more balls disappearing into the left field seats instead of landing as a double.  Both sideline reporters had submitted video evidence comparing this year's swing to last year's version to support their claims.  The clips did support Coomer and Smalley's theory however comparing one solitary swing to one other lone swing reveals very little (had they rundown over 150 swings from last year to this year I would have put more stock into their assessments). Certainly any number of small minutia adjustments could have been made to his swing in this past offseason but Mauer more or less differed and said that "I don't think my swing has changed at all."

 

Perhaps there is something less physically involved in his surge.  By Mauer's own accounts, he says that he has been "seeing the ball better".  Consider this: Mauer is absolutely killing the fastball and, on top of that, he's getting a ton of them thrown his way. 

 

Mauer's early returns in 2009 shows that he is very capable of punishing a fastball -- hitting 11 of his 12 home runs on heaters.  Fangraphs.com, who added a statistic that provides the run aboove average value of each individual type of pitch, shows that at a 5.23 runs above average, Mauer leads all hitters per 100 pitches (min. 120 PA):

 

Player	Team	wFB/C
Joe Mauer	Twins	5.23
Luke Scott	Orioles	4.62
Albert Pujols	Cardinals	4.44
Kevin Youkilis	Red Sox	4.24
Victor Martinez	Indians	4.14

 

These numbers are just another way of saying that these guys are good fastball hitters.  A few states south of Minnesota, Albert Pujols (.346/.470/.698) is demolishing the rawhide in the same vein yet Pujols only sees 53 percent of balls thrown at him as fastballs.  Likewise, Boston's Kevin Youkilis (.349/.470/.631), another hitter renown for his batting eye, and is now seeing just 54 percent of his pitches as fastballs thanks to a 4.24 wFB/C.  Cleveland's Victor Martinez (.344/.412/.555), like Youk and Prince Albert, has also seen his fastball offerings drop to the 54 percent range.  Mauer, on the other hand, has received nearly 70 percent (67.1%) of pitches thrown to him of the fastball variety.  This is a rather rotund amount considering the quality of hitter that is Joe Mauer. 

 

Look at this list of the hitters receiving the most fastballs by percentage.  Those who are getting high percentages of fastballs are of the slap-hitting, high-contact pedigree and offer very little of a power threat:   

 

Player	Team	Fastball %	Isolated Power Average
David Eckstein	Padres	75.30	.071
Luis Castillo	Mets	73.70	.056
Chone Figgins	Angels	72.80	.066
Placido Polanco	Tigers	70.40	.103
Jacoby Ellsbury	Red Sox	70.00	.068

In a lot of ways, Mauer shares similar characteristics to those on the list (unlikely to chase pitches, low strikeouts, etc) which merits a fastballs but at the same time Mauer's .405 ISOP has little in common with Placido Polanco's .103 ISOP.  The Tigers second baseman has not be able to generate any scoring when facing a fastball as evident of his -0.97 wFB/C, giving pitchers the impression that more fastballs will equal greater success against Polanco. 

 

Mauer's power surge may have to do with a greater influx of fastballs that are typically reserved for slap-happy hitters.  With a larger propensity to drive the ball for extra bases, pitching coaches will eventually instruct their pitchers to throw more offspeed and breaking pitches.  Mauer still has the ability to capitalize on what should be fewer fastballs in June but it probably means less of an opportunity to replicate his unearthly month of May.