While many boxers try themselves out in more than one division, jumping not one but two is a rare and more extreme move, sometimes ending in success, other times in disaster. Michael Spinks famously jumped from LHW to HW to beat Larry Holmes while the move from LW to WW didn't work out for Diego Corrales. Of course you can jump the other way too, think Chris Byrd unsuccessfully having a go at LHW or Vic Darchinyan first fighting at BW then settling in pretty nicely to FlyW. What double division jumps you can come up with?