The much-anticipated Harbaugh Bowl finally is here, and it couldn't be a much bigger or more meaningful game as the NFC West-leading 49ers meet the AFC North-leading Baltimore Ravens at M&T Bank Stadium with a whole lot on the line for both teams. NinersDigest identifies the keys to the game and what the 9-1 Niners need to do to beat the Ravens and match their best start since 1997.