Wednesday, March 03, 2010

Opposite Field Power or Luck?

Besides sharing the same batter’s box and uniform, there isn’t too much that Joe Mauer and Jim Thome seem to have in common. The Twins catcher prefers consuming Jimmy John’s and Land-O-Lakes milk while Thome, judging from his stature, prefers to chew raw slabs of bacon. After all, Thome’s left calf is roughly the same circumference as Mauer’s torso. Generationally Thome’s ABBA while Mauer’s Ace of Base and nearly 400 home runs separate them on the career leaderboard. However, one trait that the pair shared in 2009 was the tendency to favor handing out souvenirs to the left field bleachers:


2009 Home Runs




J. Mauer




J. Thome




*Data from


Mauer lifted 16 of his 28 home runs to left (57%) as 12 of Thome’s 23 home runs followed a similar flight pattern (52%). To be sure, this is unorthodox for lefties. Their left-handed kindred will pull 75% of his total home runs while driving just 12% to left field yet Mauer and Thome’s numbers are almost the inverse. Like most everything else about the two, the reason behind this trend couldn’t be more different.


Mauer’s directional power isn’t surprising. He has always had a high amount of his home runs leave the yard in the opposite direction but nothing like this past season. In his career, he’s elevated more pitches when he drives them to the opposite field (49.2% fly ball rate to left) versus when he pulls the ball (7.6% fly ball rate to right). If he were going to hit a significant amount of home runs, he would almost have to do it to left. What happened in ’09 was that Mauer had a higher than average amount of fly balls barely escape the playing field: 11 of his 28 home runs (39%) were categorized as “Just Enough” in distance. This 39% mark was well above the league average of 27% and is ripe for regression in 2010.  As a player in his peak-playing age, I do not anticipate Mauer to regress far – a 20-home run guy feels more appropriate.


Thome, on the other hand, has made a career of denting empty seats above the right field baggy at the Metrodome and other stadiums around baseball for the better part of the ‘90s and ‘00s. In his recent years, his penchant for bombing the right side of the field has slowed down some. In ‘07 21% of homers when to left while 19% went there last year. This frequency suddenly shot up to 52% in ’09. Meanwhile, his pull numbers went from 38% to 44% down to 17%. In addition to aging to the point where his bat speed is enviably decreasing, Thome suffered through bouts with plantar fasciitis last year, influencing his overall play. While it is possible that a fully-healthy Thome may see his distribution revert closers to his career marks at his age and health, it is just as likely as he collapses further in the power department. Given these factors, coupling on the notion that is moving away from a very hitter-friendly park in Chicago, it’s easy to expect five fewer home runs on his total (18) if given roughly the same number of plate appearances in 2010.