Many teams in the National Football League have discovered the benefits of splitting the number of carries per game between two running backs, something that has been more popular in college football in the past.

Traditionally, NFL teams have only used one feature back in their offense and used the second string running back to give the starter a breather when needed, or subbed him in on passing downs if their main guy was not good at catching passes or picking up blitzes.

This year several teams are trying out the two-back rotation system, which worked so well for schools like Auburn University, USC and the University of Minnesota.

Auburn had great success splitting the carries between Ronnie Brown and Cadillac Williams, and both ended up as top five picks in the 2005 NFL draft. Minnesota let Marion Barber III and Laurence Maroney share the ball-carrying duties in 2004 and saw Maroney rush for 1,348 yards and Barber for 1,269 yards in 12 games. Reggie Bush and LenDale White both carried the ball for USC on their way to two national championships. So it works, there is no doubt about it.

There are many advantages of running a two-back system. By rotating two backs, you keep them fresh longer into the season and reduce the risk of losing them to injuries sustained from being over worked. If a team only has one running back carrying the ball 30 times every game, he is not going to be so fresh come December when they might need him the most.

It also becomes harder for opposing defenses if they have to play a running back with fresh legs and a different running style on every play.

Some of the teams that are doing it this year are the New Orleans Saints with Reggie Bush and Deuce McAllister, the Denver Broncos with Tatum and Mike Bell, the New England Patriots with Corey Dillon and Laurence Maroney and the Indianapolis Colts with Dominic Rhodes and Joseph Addai.

Teams with the luxury of two good backs with different running styles can open up their playbook some more and take advantage of their unique talent.

There is no surprise the Atlanta Falcons have been the top rushing team in the league for the past two years. Along with a good blocking scheme, they rotated Warrick Dunn and T.J. Duckett efficiently by using their individual skills as runners depending what situation they were in. Of course, having quarterback Michael Vick contribute with more than 500 yards rushing each of the two years helped out as well.

What could cause a problem for some players who have never split the workload before might struggle to find their rhythm in the games, which could mean less yardage. Players with bonus clauses in their contracts relating to total rushing yards per season probably will not like this system too much, at least not until they sign a new contract.

For people playing fantasy football, the two-back system is blasphemy. Having Tiki Barber as your starting running back sounded like a great idea until he wanted to share his carries with Brandon Jacobs.

The coaches probably love it, because their main back will still have somewhat fresh legs for the playoffs.