Panthers' Steve Smith flips after missing a catch against Seahawks' Richard Sherman during the third quarter of an NFL football game in Charlotte, N.C., Oct. 7, 2012. (AP Photo/Nell Redmond)

Browns running back Trent Richardson flips into the end zone at the end of a touchdown run in the first half of a game against the Bengals, Sept. 16, 2012, in Cincinnati. (AP Photo/David Kohl)

Chargers running back Ryan Mathews flips into the end zone as Saints middle linebacker Curtis Lofton (50) and free safety Malcolm Jenkins (27) defends at the Mercedes-Benz Superdome in New Orleans, Oct. 7, 2012. (AP Photo/Bill Haber)

Steelers wide receiver Antonio Brown, left, flips into the end zone over Colts defensive back Antoine Bethea for a touchdown in a preseason game, Aug. 19, 2012 in Pittsburgh. (AP Photo/Don Wright)

Vikings quarterback McLeod Bethel-Thompson flips over Texans linebacker Shawn Loiseau during a preseason football game, Aug. 30, 2012, in Houston. (AP Photo/Pat Sullivan)

Panthers quarterback Cam Newton dives into the end zone for a touchdown as Falcons' Chris Owens pursues during the second half of a game in Charlotte, N.C., Dec. 9, 2012. (AP Photo/Rainier Ehrhardt, File)

Giants wide receiver Victor Cruz is flipped over by 49ers cornerback Carlos Rogers during on an incomplete pass during the second half of a game in San Francisco, Oct. 14, 2012. (AP Photo/Mark J. Terrill)

Browns running back Trent Richardson flips into the end zone for a touchdown against the Bengals, Sept. 16, 2012, in Cincinnati. (AP Photo/Tom Uhlman)

Patriots linebacker Niko Koutouvides flips over Buccaneers running back Michael Smith during a preseason game, Aug. 24, 2012, in Tampa, Fla. (AP Photo/Chris O'Meara)

Giants running back David Wilson flips after scoring on a 6-yard touchdown run against the Saints in East Rutherford, N.J., Dec. 9, 2012 (AP Photo/Kathy Willens, File)