Evaluating the price per carry

Shannon's Enquirer story today takes a look at Rudi Johnson -- 14 pounds lighter with a new diet -- and the success he's had against the Browns:

Over the last five Bengals-Browns games - all Bengals wins - Johnson has averaged 141.4 rushing yards and a touchdown.

In nine career games against Cleveland, Johnson rushed 183 times for 890 yards and nine touchdowns and has caught 15 passes for 67 yards.

And this: Johnson's career-high rushing game came against Cleveland in 2004, when he amassed 202 yards on 26 carries.

This was nice timing for this story, because I've been wondering the past couple days how long Johnson is going to be able to remain the feature back the Bengals have relied upon him to be. He plays a position that is well noted for its short lifespan in the NFL and he does it in a rugged manner. Consider that no NFL running back had more carries than Johnson from 2004-2006. Johnson ran the ball 1,039 times, an avergae of more than 21 carries per game. In that time, he finished 6th, 7th and 7th in the NFL in rushing yards. Including Johnson, of the top six rushers in 2004, only three are left in the league. Curtis Martin, Tiki Barber and Corey Dillon have retired.

So here goes Johnson after three demanding, productive seasons into a 2007 season that might be the most demanding yet for him, considering there isn't much behind him on the roster to lighten the load for the next several weeks. What kind of toll is a big game against the Browns going to take; when's it going to show up; and how's it going to affect the Bengals?

Maybe the answer is that Johnson is tougher and more hardy than the average back, leaving no reason to worry. Or maybe not. It's worth discussing.