The 2007 Tampa Bay Devil Rays were an unfathomably ugly team to watch. They ranked dead last in baseball with a 5.53 ERA. Their bullpen also fared worse than anyone else, putting up a stupendously bad 6.16 ERA. The pitching staff was manned with plenty of arsonists, to be sure. But what made this team truly terrible, and truly horrifying to watch, was its defense. When you get to hell, the first thing you'll see will be highlights of a young Delmon Young flailing after fly balls.

The 2008 Tampa Bay Rays changed everything. They ratcheted up the bullpen. Promoted top prospect Evan Longoria to the majors and watched him excel right away. And when it came to defense … you would never believe this was the same team from a year earlier. Because it wasn't. Baseball Prospectus tracks a defensive stat called Defensive Efficiency, a Bill James creation that measures the frequency with which teams turn balls hit in play into outs. Using that stat, the '08 Rays saw the biggest year-over-year improvement of any team in 50 years. The story of the Rays' improbable rise from worst to first — and their subsequent run of three playoff berths in four years playing with limited resources in the toughest division in baseball — is the story of a team that learned many lessons, none larger or more important than the value of defense.