So what types of plays can coaches challenge, and what calls on the field cannot? What can NFL coaches challenge? It's also up to the judgment of referees to signal an officials timeout inside the two-minute mark if something deserves a second look. Scoring plays are automatically reviewed by officials. A failed challenge results in a loss of timeout, and two failed challenges mean that their team will not have a chance to challenge a call for the rest of the game. It's important for head coaches to make wise decisions when it comes to whether or not to use their challenge flag. Others, like Mike Tomlin of the Pittsburgh Steelers, have difficulty coming away victorious more often than not when they let the challenge flag fly. Some coaches have a good track record when it comes to this. In the NFL, head coaches have the ability the launch their red flag onto the field - signaling that they would like to challenge the previous play. But the National Football League has a method in place for combating questionable calls - it's called the challenge flag. Unfortunately for NFL referees, these mistakes come when millions of eyes are watching them. Like people in any and every profession, occasionally, they get things wrong from time to time.

This might be news to you, but referees aren't perfect.