Whenever I converse with a fellow Buffalo Bills fan about running back C.J. Spiller, the general sentiment of the party I'm speaking with is that Spiller will follow the same career arc as Jamaal Charles of the Kansas City Chiefs: shaky as a rookie, then one of the league's best backs. The theory is that Spiller and Charles are players with similar size and running styles.
My universal retort, aside from my usual "stay away from player comparisons" rant, has been that it's just as likely - if not more likely - that Spiller's career path bears a stronger resemblance to Darren McFadden of the Oakland Raiders. That has nothing to do with size or running style, by the way.
Charles was always an effective runner, even as a rookie; Chan Gailey held him off the field because of fumbling problems. He averaged a full 1.5 more yards per carry than Spiller did as a rookie. McFadden, meanwhile, came out of Arkansas with freakish athleticism and took two full years to acclimate to the NFL, rushing for a combined 856 yards in that time frame while dealing with injuries and, again, fumbling problems.
Spiller faces many of the same challenges McFadden finally overcame in his third season (1,654 total yards, 10 touchdowns): adjusting to a game in which he can't get by on pure athleticism, and must hone his patience and become a more decisive and reliable runner. Here's hoping that if Spiller can't replicate Charles' success, that he'll at least blossom more quickly than McFadden did.