Luke Willson (#82) of the Seattle Seahawks celebrates after scoring on a two-point conversion during the fourth quarter of the 2015 NFC Championship game against the Green Bay Packers on Sunday. Seattle won 28-22. Tom Pennington/Getty Images hide caption

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Boyd Dowler of the Green Bay Packers grabs a Bart Starr touchdown pass in the NFL championship game on Dec. 31, 1967. The "Ice Bowl," played in frigid temperatures, was won by the Packers 21-17. AP hide caption

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Confusion: One official (to the left) signals touchdown for Seattle. The other signals that a touchback — possession — for Green Bay. Stephen Brashear/AP hide caption

itoggle caption Stephen Brashear/AP