Just how does that yellow first down line work?

Name: Just how does that yellow first down line work?
Uploaded: 2015-01-27T15:15:06Z
Duration: 2 min 18 s
Description: When Super Bowl XLIX kicks off on Sunday, it will utilize a piece of technology that has changed the viewing of the game, and grown into a new industry of graphics in sports television. (Jan. 27)

When Super Bowl XLIX kicks off on Sunday, it will utilize a piece of technology that has changed the viewing of the game, and grown into a new industry of graphics in sports television. (Jan. 27)