Backup running back Bernard Pierce has been the biggest surprise of this year's Ravens draft class. Pierce has led the Ravens in rushing in two of Baltimore's three playoff games, averaging 6.3 yards per carry this postseason.

The Ravens can thank Ricky Williams for having Pierce on the team this season. If Williams hadn't announced his retirement last Feb. 7, which caught Baltimore off guard, the Ravens probably wouldn't have drafted Pierce in the third round because there would've been no need for a No. 2 running back.

"He’s a tackle-breaker and he’s explosive," Ravens general manager Ozzie Newsome said of Pierce. "He’s a good match to what Ray [Rice] is, and he was there for us to pick in the third round. And you know what? For him to sit there and be in the meetings with Wilbert (Montgomery, running backs coach) and Ray (Rice), and to be able to learn the importance of protection and all those other things, it’s just very beneficial.”

No one has benefited more from the change in offensive coordinators than Pierce. In his first 13 games this season, all under Cam Cameron, Pierce was on the field 17 percent of the time, according to ESPN Stats & Information. In Jim Caldwell's six games, Pierce has been on the field for almost one-third of Baltimore's snaps.

Pierce, who finished as the second-leading rusher in Temple's history, has taken advantage of the extra playing time. In his six games with Caldwell, Pierce has gained 401 yards rushing (66.8 per game). He totaled 300 yards rushing in the 13 games that Cameron called plays.

Pierce was the seventh running back taken in the 2012 draft. One of the backs selected before him was LaMichael James, a second-round pick who is playing for the 49ers in the Super Bowl.

"We’ve seen in this league now, you need two backs," Newsome said. "When we’re back [at the NFL scouting combine], Wilbert always takes the opportunity to go down on the field when the running backs are working, because he played the game. He came back and he said, ‘I’m impressed with this guy Pierce.’ He brings a different dimension."