No lead safe? Comebacks in mind this week

The Chicago Bears are visiting the Arizona Cardinals in Week 16 for the first time since the 2006 game that launched Dennis Green into beer commercial history.

The Bears overcame a 20-0 halftime deficit to win, 24-23. Green was not happy about it.

On Sunday, the San Francisco 49ers posted a 41-34 victory over New England after blowing a 31-3 lead. Hours earlier, the Seattle Seahawks attempted a fake punt while holding a 47-17 lead over the Buffalo Bills in the fourth quarter.

These three storylines share a commonality. All invite questions about when a lead is large enough for a team to feel comfortable enough about its chances to play less aggressively.

That Bears-Cardinals game was notable for Green's postgame rant. The comeback itself was impressive, but the score was 23-10 after three quarters. Teams have overcome deficits that large entering fourth quarters three times since 2010 and 24 times since 2000.

The chart shows comeback victories from 20-plus points after three quarters since 1940, courtesy of Pro Football Reference. There are fewer of those.

Only four times since 1970 has a team leading by 30-plus points through three quarters won by 14 or fewer points. It happened most recently in 2006 when the Seattle Seahawks claimed a 42-30 victory over the New York Giants after leading 42-3 through three quarters.

The 49ers held a 31-10 lead over the Patriots through three quarters on Sunday. New England scored a touchdown on the first play of the fourth quarter. Even at that point, the 49ers' win probability was around 95 percent. The Seahawks' win probability was above 99 percent when the team gained 29 yards on its fake punt.

ESPN Stats & Information calculates win probability based on similar game situations and outcomes from the past 10 seasons.

Most of the memorable comebacks from large deficits were accomplished over multiple quarters.

1940-2012: Teams Winning After Overcoming Deficites of 20+ Points Through Three Quarters