The Detroit Lions had a 17-point halftime lead against the San Francisco 49ers (24-7) in the NFC Championship until they unraveled in the second half and lost 34-31. With the loss, Detroit broke a Green Bay Packers record in the NFC Championship Game by blowing a 17-point when leading at the half.Green Bay had a 16-point lead at halftime in 2014 in the NFC Championship Game against the Seattle Seahawks, until they lost 28-22 in overtime against Seattle. The Packers fanbase remembers that game well, unfortunately.When the Detroit Lions were leading by 17 points at halftime against the San Francisco 49ers, teams were 17-0 all-time in Championship Games when they had a 17 or more-point lead at halftime. Detroit finished the season 12-5 and won the NFC North. There were some decisions in this football game that ultimately cost the Lions.