Through 538 plate appearances this season, Fielder has put up a .204 isolated slugging percentage (ISO). That's great by most standards, and 22 home runs is nothing to sneeze at, but it would be the lowest of his major league career since he became a full-time player in 2006. He did post a .209 ISO in 2010, but was also walked/hit by pitch a combined 135 (!) times and had a career-worse strikeout rate that season. And he's only 28; it's a little early in his career for him to be experiencing a power decline. And while offense as a whole is down, home runs are becoming more common. League-wide, the HR/FB rate is about two percentage points higher than in either of the previous two seasons. So is this just a fluke season, or is there something more to this?
Some of you may point out that he won the home run derby this year, but I'll also point out that Bobby Abreu once won a home run derby.
There are some easy explanations as to why his power may be lacking. One is by moving to Detroit he's moved to a tougher league in the AL, and as we've seen with fellow slugger Albert Pujols, it can take some time to adjust to new pitchers, ballparks, and strategies employed by his new foes. Another explanation is that he's altered his approach and sacrificed some power to become a better overall hitter, something he's hinted at for years. He's cut down on his strikeouts in a big way, but his walks have also suffered and his batting average is very good but not eye-opening. He's also switched to a tougher ballpark, and while Detroit's Comerica Park has been considered a pitcher's park by most people, in actuality it's bounced around in the rankings the last few years as far as park factors are concerned. One thing is for sure, Comerica suppresses home runs more than your average park, while Miller Park does exactly the opposite.
Miller Park has always been viewed as an extreme hitter's park, but prior to this season, that hasn't been accurate. The perception has been aided by the fact that the Brewers have had good offenses the last few years while also trotting out underwhelming pitching staffs. In reality, MP is a great home run park, but doesn't encourage other forms of offense and in fact is pretty close to neutral even with the home runs. But this year, offense has been out of control in Milwaukee. It went from being a good home run park to a balls-out ludicrous home run park, and it's been the best in the majors by a large margin. The best explanation I can come up with is the effects of the weather, as the summer heat helps the ball go a long ways and this summer has been hotter and drier than any in recent memory. This also helps explain why home runs have been on the rise in most of the parks not on the West Coast, where the ocean air helps keep the dry, hot air in check.
Someone about to hit a home run, probably.
So while the miserable hotness has helped increase bombs in most parks (Comerica included), it's really helped Miller Park, the place the Prince Fielder used to call home. And while he's certainly not experiencing an Adrian Gonzalez-level power outage, the Tigers didn't give him $214 million dollars to hit 29 home runs every year, which is what he's on pace for in 2012. Would he hit more bombs in Milwaukee? Almost certainly, but there's no doubt he's happier with the millions Detroit is paying him.