Baby, you're a firework

Some running backs shoot through the tubes with a whoosh, rifle into the sky above the Friday night lights, and explode in the end zone in a flash of red and blue.  They draw "oohs" and "ahhs" from the crowd, and make old men want to be young.

As a Texas schoolboy Adrian Peterson ran for 2,960 yards and 32 touchdowns in one season.  At the NFL combine a few years later they timed him in 4.38.

Impressive gifts, but LeGarrette Blount became a 1,000-yard rusher his first season in the league with a top combine 40 time of 4.62.

In evaluating young running backs like Tra Carson, it's important to keep in mind there is more than one way to dazzle the crowd.  Some do it with power, some with raw speed, others with a combination and rare vision.