Perhaps no one in professional sports experiences as much wear and tear than your NFL workhorse running back. Guys like LaDainian Tomlinson, Shaun Alexander, and Terrell Davis—players who frequently received over 300 carries per season—tend to wear out before their 30th birthdays.
With this in mind, so many teams are switching to a two-back system, or even a three-headed running game, to increase the lifespan of their backs.
In this past NFL season, their starting running backs—DeAngelo Williams and Jonathan Stewart—combined for 457 carries, 2,351 yards, and 28 touchdowns, while only fumbling twice. Despite only a mediocre season from quarterback Jake Delhomme, the Panthers still finished 12-4 and captured the NFC South.
The Ravens implemented a three-headed system, using veteran Willis McGahee, first-year starter Le'Ron McClain, and rookie Ray Rice.
Those three, each receiving over 100 carries, accounted for just over 2,000 rushing yards and 17 touchdowns on the ground, helping the Ravens become the fourth best rushing offense in the NFL.
Meanwhile, the Giants had one of the most successful trios in recent years. They rotated big, bruising back Brandon Jacobs (1,089 yards, 15 touchdowns) with smaller, faster players like Derrick Ward (1,025 yards) and Ahmad Bradshaw (355 yards).
All three players averaged over five yards per carry, as the Giants rode their ground game to 12 wins and an NFC East title.
These three teams show how NFL teams are beginning to refrain from featuring one man in the running game. Giving a back too many carries is almost certain to wear him down and lead to an injury from which he will never return from the same.
In 1998, ten players received over 300 carries, with five of those players—Jamal Anderson, Terrell Davis, Curtis Martin, Eddie George, and Barry Sanders—topping 340 apiece. This past season, just five players carried the ball over 300 times, and only three players—Michael Turner, Adrian Peterson, and Clinton Portis—topped 340 carries.
This is a direct result of teams using their backup and third-string running backs even more. In today's game, the ideal running game features a power runner, like Marion Barber, and a speedy, elusive guy who can get outside the tackles, like Felix Jones. Players like these compliment each other very well and give the offense a change of pace.
Teams with the speed guy often look to draft a power back, just as teams with the power back keep their eyes open for a speed guy to add to their roster. Fewer and fewer teams give a guy 80 to 90 percent of the carries, as overworking them comes with an almost certain risk of injury.
Look at Larry Johnson as an example. Johnson was used sparingly his first two seasons ('03 and '04). In '05, Johnson received 336 carries, rushing for 1,750 yards and 20 touchdowns. The next season, he set a new NFL record with 416 carries while accumulating 457 touches. He led the NFL in rushing yards (1,789), but his yards per carry dropped virtually a whole yard (5.2 to 4.3), and the workload began to affect him.
In both '07 and '08, he was hurt, never carrying the ball more than 200 times in either season. Almost 30 years old, there doesn't seem to be much of a future left for Johnson, who is one of a number of backs whose career has been shortened due to his excessive workload.
Terrell Davis of the Broncos averaged 336 carries his first four seasons, increasing his workload each year, before topping out at 392 carries in '98. In his last three seasons, he never played more than eight games, averaging just over 100 rushes per year, before retiring in '01.
Running back is arguably the most physically demanding position in the game. Other than the physical freaks of nature like Jim Brown, Barry Sanders, Emmitt Smith, and Walter Payton—guys who racked up 300 or more touches year after year—no one player can sustain the constant pounding the position demands.
As stated earlier, ten players rushed the ball more than 300 times in 1998. This past season, that number was down to just five.
In '98, 39 players carried the ball more than 100 times. This season, that number was up to 48.
And in '98, just one team had multiple players each carry the ball more than 150 times. This year, there were four separate teams that fit that qualification.
Teams are preferring the multi-back system more and more. And those that utilize it are more often than not successful.