NASCAR has one person holding the most important and closely watched job at each Nextel Cup race. It's the flagman, who has a palette of flags from which to communicate the wishes and demands of race officials.
Here is a rundown of the flags waved from high atop the start-finish line at each race:
Green -- Like a green light signaling go, this signals the start of the race. Before the green flag flies, a pace car with flashing yellow lights on top leads the field around the track to warm up their tires and engines. Just as the pace car speeds into pit road, the green flag is waved to unleash the furious excitement.
The green flag also comes out to signal the resumption of the race after a caution, or yellow, period.
Yellow -- The caution flag, or as it's better known lately "the let's tick off Tony Stewart flag." OK, just kidding about that last one after the outspoken driver accused, then retracted, his likening of NASCAR to pro wrestling and accusing officials of trying to influence races by pulling out the yellow flag for the smallest of track debris.
But seriously, NASCAR does not take the yellow flag lightly. Safety is of highest importance, so the yellow flag is waved for the safety of everyone near the track be it drivers, pit crews, track workers, NASCAR officials or fans. Accidents, rain, debris or oil on the track will prompt race officials to quickly fly the yellow flag.
Once the yellow flag is waved, the order of the racers is frozen and drivers can't pass during a yellow. They must stick to their positions and slow to a predetermined pace in a single line behind the pace car.
Stewart was right about one aspect of the yellow flag: that fans don't want to see a race run mostly under a caution. And there's usually at least one driver unhappy to see the yellow pulled out. That's the leader, especially if he's way in front, because restarts after yellow flags bring racers back into a pack, tightening the biggest of leads down to a fraction of a second.
Red -- As you might have guessed, or any preschooler can tell you, this means stop. But when the red flag is waved in a race, drivers must fall in line behind the pace car that has stopped on the track.
Race officials fly the red flag when they need the race stopped immediately, such as for safety or competition-related instances. Reasons for a stoppage could be a damaged wall, rainfall or a dangerous amount of oil or fluid on the track.
Unless a car has withdrawn from the race, no one is allowed to take a pit stop for fuel or repairs during a red flag.
Drivers are allowed to park their cars in the pit stalls during red flag periods for rain.
Black -- This is bad news if your car gets black flagged. The driver must get off the track and into the pits immediately for inspection. While the black flag can signal a disciplinary infraction -- such as jumping the start -- or sometimes disqualification, it could stem from a mechanical problem creating dangerous conditions that merely calls for the vehicle to get off the track.
If a driver doesn't respond as he is required to quickly enough to the black flag, the flagman will pull out the black flag with a white "X" across it. This signals that the car will no longer receive any scoring, so just give up and and head to the pits.
Blue with diagonal yellow stripe -- This one would come in handy on the Interstate. Slow cars that are a lap or more behind can get this one waved at them, signaling these drivers to let the faster lead-lap cars pass them without any blocking.
White -- The penultimate flag, hopefully, this signals that the race leader is on his final lap of the race.
Checkered -- This is waved as the race winner crosses the finish line and again for every car that finishes the race.