Because they are losing, big time!

Before the season, Tom Coughlin had one of the more successful records (47.6 percent) on replay challenges among N.F.L. coaches. Not this season. His success rate fell to 30 percent.

“We must be, what, 0 for 100 by now?” Coughlin said earlier this week.

Not quite, but it might feel like that. The Giants have lost their last eight challenges, including a particularly notable call in their victory over the Packers, which vaulted them into Sunday’s N.F.C. championship game against the 49ers in San Francisco.

So when was the last time Coughlin and the Giants won a challenge? Week 2, in the third quarter of their victory over the St. Louis Rams.

He used to be better, though.

Historically, the Giants have done well by Coughlin’s method. Only once in Coughlin’s seven seasons before this one had his challenge success rate been lower than 40 percent. In 2008, he was successful 75 percent of the time.

This season has been different. Coughlin was only 3 of 10 and was 0-1 in the playoffs after a disputed non-fumble by Packers receiver Greg Jennings.