A Look at the NFL's Top 20 Running Backs

This is an era when Super Bowl games are won by only passing teams that can run the ball if they have to.

Whenever an NFL game matches good team vs. good team, no ballcarrier can make the difference today.

Even so, a balanced threat is as essential as ever. The best passing teams can't succeed without a running threat.

So who are the best of the active running backs? Here are my top 20:

1. Larry Johnson, Kansas City -- This year's new sensation, Johnson, complementing quarterback Trent Green, is a classic power back who can change himself into a scatback in the open field and continue on with great speed and moves.

2. Shaun Alexander, Seattle -- Also coming on this year, Alexander, complementing quarterback Matt Hasselbeck, may lack the speed of the NFL's fastest backs, but he's an impressive slasher with power who can move in the open.

3. Tiki Barber, New York Giants -- The kind of back that LaDainian Tomlinson is supposed to be, Barber has the speed and moves that the great backs have always brought to football plus the drive to run through tackles.

4. Clinton Portis, Washington -- Something of a Tomlinson type as well, Portis is faster and more assertive in the hole and makes better moves at higher speed down the field

5. Edgerrin James, Indianapolis -- With the upper-body strength to keep going in close quarters, James, complementing Peyton Manning, excels in the hole and in the first five to nine yards. He also excels in the science of attacking tacklers where they're weakest.

6. Corey Dillon, New England -- A heavy-duty power back, Dillon lacked production this year because of the Patriots' ill-fated shotgun-formation experiment and to injuries. Still, now that the Patriots are rolling again, a major explanation is that an injury-free Dillon is giving passer Tom Brady another weapon.

7. Fred Taylor, Jacksonville -- Greatly talented, Taylor is a cross between a power back and a sprinter who can go, and if he could remain injury-free he'd rank higher.

8. Warrick Dunn, Atlanta -- Another Tomlinson type, Dunn at 180 pounds outperforms the much heavier Tomlinson in every respect from moving the pile to running away.

9. Curtis Martin, New York Jets -- A hard-yard specialist, Martin is a pros' pro, getting most of his yardage after the first hit.

10. Tomlinson, San Diego -- Though he has some open-field speed and moves, Tomlinson can't pound or drive for the hard yards and is too frequently shut down to be a threat you can count on.