Posted by ESPN.com's Mike Sando
NFL head coaches become powerless when close calls threaten to influence outcomes in the final 2 minutes of halves.
During these pressure-packed minutes, coaches rely upon largely anonymous instant-replay officials to challenge referees' rulings on their behalf. The challenge system, in place since 1999, has worked well enough for team owners to keep it around.
The league assigns the same replay officials to the same referees each week. As the chart shows, some referees face challenges in the final 2 minutes far more often than others.
A couple of sequences stand out from this season.
In Week 10, replay official Bob Mantooth challenged referee Tony Corrente after the Cardinals tackled the 49ers' Frank Gore short of the goal line in the final seconds. The challenge superseded a penalty against the 49ers that would have resulted in a game-ending clock runoff. Corrente upheld the ruling on the field and the Cardinals prevailed.
In Week 12, replay official Al Hynes challenged referee Gene Steratore after officials credited the Colts' Marvin Harrison with a 5-yard gain on a third-and-5 play with 41 seconds remaining at San Diego. Steratore reversed the first-down ruling. The Colts went for it on fourth down and converted before Adam Vinatieri's 51-yard field goal broke a 20-20 tie.
If replay officials applied the same standards each game, we might expect referees to face a similar number of booth-initiated challenges over time.
That was not the case in past seasons and it's not the case in 2008. Corrente and Steratore have each faced 10 booth-initiated challenges this season, as has Ron Winter. Four other referees -- Carl Cheffers, Bill Carollo, Jerome Boger and Mike Carey -- have faced zero combined challenges from upstairs.
It's something to keep in mind the next time a controversial call aruses in the late going.