Exactly.

[MadScientist]

Explosive runs might be a good metric with some teams, but for other offenses the more important variable might ability to pick up consistent positive yardage on 1st and 2nd downs. Even when he was good Chris Johnson would lose yardage on a high percentage of his runs. For an offense like Green Bay's that depends on maintaining manageable down-and-distance, Johnson would not be nearly as valuable as a guy like Lacy who consistently moves forward.

Not sure about that. How much will a DC scheme to stop a guy who gets 4 +/- 2 yards a carry vs a guy who has a fair number of -2 to +3 yard runs but will go 20-60 yards if the defense every 10th run, especially if the defense is napping?

[hoosier]

Not sure about that. How much will a DC scheme to stop a guy who gets 4 +/- 2 yards a carry vs a guy who has a fair number of -2 to +3 yard runs but will go 20-60 yards if the defense every 10th run, especially if the defense is napping?

With the Packers I think the second kind of RB is just duplicating a threat that the passing game can carry out more effectively. If you're the DC facing the Packers and you have to choose between letting Rodgers beat you throwing or a Chris Johnson type break off the occasional long run sandwiched around a bunch of negative runs, that is a pretty easy choice to make. Chris Johnson's all-or-nothing is much less scary than Rodgers throwing against an eight man front. So is Lacy's four-to-six, except a defense can't let Lacy do that to it all day long.

[3irty1]

With the Packers I think the second kind of RB is just duplicating a threat that the passing game can carry out more effectively. If you're the DC facing the Packers and you have to choose between letting Rodgers beat you throwing or a Chris Johnson type break off the occasional long run sandwiched around a bunch of negative runs, that is a pretty easy choice to make. Chris Johnson's all-or-nothing is much less scary than Rodgers throwing against an eight man front. So is Lacy's four-to-six, except a defense can't let Lacy do that to it all day long.

Just devils advocate but there is something to be said as well for a guy who can do a ton of damage with fewer snaps. Guys like that can keep play action viable without having to blow all the clock it takes to establish the run with a guy like Lacy. Generally shortening the game increases the likely hood of an upset so on a great passing team it could make sense to desire running the minimum amount of running plays that are required to keep defense honest.