The biggest story line for the Kansas City Chiefs this offseason is the health of the three players who tore their ACL last year, namely Jamaal Charles, who is the key to the Chiefs offense in 2012. The question with Charles is not whether he can come back from his injury -- he will come back -- but how effective he can be in his return.

There's no definitive data on how players perform after ACL surgery because there are so many factors involved but they're usually not completely 100 percent of what they were pre-injury, at least for the first year or so.

The one comparison I would like to see with Charles is Jamal Lewis, who tore his ACL in the 2001 preseason, around the same time of the season Charles tore his (Week 2). Lewis was 21 years old at the time; Charles was 24 when he tore his.

Lewis' stats in the year before his ACL tear and the year after were largely the same -- around 1,300 yards rushing with six touchdowns. As Adam Levitan of Rotoworld writes, Lewis is among the top success stories.

In terms of success stories in the year following ACL tears, Jamal Lewis is at the top of the list. But note the unique circumstances here. Lewis was just 21 and his injury occurred in the preseason, giving him 13 months to get ready for the 2002 season. It sounds a little like Jamaal Charles' current situation.

In six of his next seven seasons after the ACL tear, Lewis had at least 1,000 yards rushing (with 906 yards in the one year under 1,000).

If you're looking for a comparison, Jamal Lewis might be the best case scenario.