Exactly.

[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.