Kevin wrote a great analysis last Monday on the Green Bay Packers running back situation. But I don't have as much confidence as Kevin in regards to RB James Starks. I like how hard he runs, and he didn't have a single fumble. He turned the Packers running attack into something you had to consider during the playoffs.
But he did not bring the big ground play. The team only had 3 carries for more than 20 yards on the season, and I don't know if that included the 27 yard run by Starks during the Wild Card game in Philadelphia. Each running back relies heavily on his teammates until he can get into the second level against the linebackers and defensive backs. Then it's up to the running back to make the big play.
And Grant is a big play machine. He had eight carries for more than 20 yards in 2009, which I learned from this excellent analysis at the Star Tribune that compares Grant favorably to RB Adrian Peterson. No running back on the 2010 Packers showed that he could produce those big runs through the second level, which is why I expect the Packers are looking forward to Grant's return next season.