15 games into Joe Mauer's 2009 season, he is hitting .429 with an astounding six HRs. For a player whose HR totals the previous two seasons were 9 and 7 and who has hit double digit HRs in just one of his nine professional seasons (13 in 2005), the HRs seem to be either a fluke or a signal that the 6'4, 220lb Mauer has finally developed the power his frame would dictate he had.
I admit to thinking there may be more to this power surge than luck, but I wanted to see how unusual this power surge has been. To do so, I looked at Mauer's game-by-game major league career using Baseball Musings' Day-by-Day database.
Using rolling 15-game periods, one can see that Mauer has never had a stretch like the one he is currently in. The most HRs he has hit in any 15-game stretch is four, and that was last accomplished in 2004.
|Year||# 15G Periods||0 HR||1 HR||2 HR||3 HR||4 HR||5+ HR||Highest AVG||% Period start 0 HR|
As interesting is the fact Mauer's .429 AVG has not been the best he has had in his career. In fact, Mauer seems to be capable of hitting in the .400 range over 15 games every season. (>.395 3 times in 2008, 4 in 2007, 33 times in 2006, none ion 2005 and 2004).
Of course, looking beyond this data shows Mauer with an incredibly high flyball percentage. 48.6% in 2009 is greater than the sum of his past four season's FB%s - 34.9%. An actual increase in his GB% points towards this surge being temporary.
So why do I think there could be more to this surge than an incredibly high FB%? The sacroiliac injury. The efforts to manage the injury could have changed Mauer's stance just enough to help his power. Normally, we think of an injury causing a negative cascade towards other injuries, but is there any reason to think compensating for a condition couldn't help?