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What’s Wrong With Adam Dunn?

Adam Dunn is one of the most durable, consistent power hitters in baseball. When Chicago inked the 31-year-old to a four year, $56 million deal last offseason, there was no reason to suspect anything less than the .250/.380/.520 that he puts up seemingly every season. However, through the first month of the season, Dunn is hitting .171/.308/.316. Is The Big Donkey going to rebound, or should the White Sox be concerned about their DH?

It often gets mentioned when discussing Dunn, but his consistency over the last several seasons has been so absolutely amazing that it’s worth rehashing one more time. His home run totals starting in 2005 are: 46, 40, 40, 40, 40, 38, 38. His RBI totals over the same time frame: 102, 101, 92, 106, 100, 105, 103.

In fact, all of Dunn’s yearly graphs are ridiculously stable. Compare those graphs to some of his contemporaries: Jim Thome, Pat Burrell, and current teammate Paul Konerko. Even when compared to those consistent sluggers, Dunn’s graphs look like they were drawn with a straight-edge.

There are three reasons why Dunn is struggling so far: a) he has been a victim of the luck dragon; b) he has not found his power stroke; c) his strikeouts are up.

For the luck, Dunn’s BABIP is only .238 so far in 2011. While he has had two seasons under .260 in his career, there is no reason why his BABIP should not creep closer to his .295 career average as the season progresses.

As for Dunn’s power outage, his ISO is only .145 to start the season, more than 100 points off his career average. Dunn has never posted a season ISO under .200 in his career (side note: Juan Pierre has never had one over .100). For a guy with legendary consistency, it is highly unlikely that he will keep up a pace which is 25-percent lower than his worst season.

Dunn’s home run per fly ball rate looks unlucky as well. His HR/FB rate this year is 12.5-percent, almost half his career average of 22.1-percent. If he signed with San Diego this might be an area of concern, but the White Sox play in one of the most homer-friendly parks in the league. It is only a matter of time until Dunn’s HR/FB rebounds.

Dunn’s low BABIP may be contributing to the power outage as well. His BABIPs are lower on all three batted ball types (grounders, liners, and flies) than they were last year. The grounders probably would not help his power numbers much, but some more balls falling for hits on his line drives and fly balls would certainly contribute to his ISO.  Dunn’s BABIP on liners this year is .750 and .095 on flies. In 2010, those numbers were .815 and .200, respectively.

Dunn has always been a high strikeout player, but Dunn’s 40.1-percent strikeout rate this year would be a career high. Digging into his plate discipline numbers suggest that his strikeout struggles may be due to the improved pitching of the American League. Dunn is swinging at 61.8-percent of balls inside the strike zone, and of those swings, he is making contact 73.2-percent of the time. Both of those numbers are career lows. Unlike BABIP, swing and contact numbers are completely controlled by the player. Right now, Dunn is just not seeing the ball well. He is not swinging at balls in the strike zone, and even when he does he is not making good contact.

A pessimist would say that the swing numbers are proof that Dunn is aging and/or the tougher American League is chewing him up. While this may be true to some degree, the more likely answer is that Dunn is adjusting to the new league, and his plate discipline numbers will rebound to more familiar levels by the end of the year. The move to tougher league might mean that Dunn has his worst strikeout season ever, but even if that happens, it will probably be at around 37-percent, not 40-plus.

Not everything about Dunn’s 2011 campaign is down. He is walking more than he did last year, 15.4-percent to 11.9-percent. Also, he is hitting a ton of fly balls; 53.3-percent, a career high. Those factors will play very will in U.S. Cellular Field if his strikeout and power numbers rebound as predicted.

In his career, the Big Donkey has been more like the Big Work Horse. His hitting profile is well established, and it is very unlikely that his contact and power disappeared overnight. With a little adjustment and some better luck, Dunn will finish near the 40 home runs and 100 RBIs that everyone penciled in for him this season.