In Sunday's 19-17 loss to the Green Bay Packers, Ravens coach John Harbaugh made the controversial decision to go for a touchdown on fourth-and-goal from the 1-yard line in the first half. It was controversial, of course, because it didn't work. It was a calculated risk, though, one many other coaches also would have taken. It wasn't the first time Harbaugh had rolled the dice on fourth down, and it won't be the last. In this week's Five for Friday, Matt Vensel looks back on five of Harbaugh's other fourth-down gambles.