Adam Dunn signed a four-year, $56 million contract with the Chicago White Sox after the 2010 season. He was supposed to be the big bat in the Southsiders' lineup as they try to regain traction in a very competitive AL Central.

But now the White Sox are having big-time buyer's remorse.

More than halfway through the season, Dunn is hitting a dismal .163 with just 11 home runs but already 142 strikeouts. He's on pace to set career lows in batting average, home runs and RBIs but maybe a career high in strikeouts. His OPS has plummeted from a career average of .902 to just .596 this season.

Dunn's struggles, however, aren't unprecedented. Just three years ago, the same kind of implosion (or worse) happened to Andruw Jones, who went from a perennial All-Star and Gold Glover to worthless bum in just one season, right after signing a fat free agent contract with the Dodgers. Other big names have been similarly afflicted, including the likes of Mark McGwire, Jose Canseco, Adrian Beltre and Sandy Alomar.

With the OPS as our guide, we combed through the most precipitous falls from one season to the next. And these are what we came up with for MLB's Biggest Career Dropoffs (in the Wild Card Era):