Obviously, the team with the most speed overall has a huge advantage over the rest of the field, but only if it works as a team. That can be a problem, given that sprinting is traditionally the realm of the biggest egos in the track world. If all the members of the relay team don't buy in to the team concept, all their speed might be for nothing.

"A lot of people underestimate how hard it is to work together," says Glenroy Gilbert, a member of Canada's gold medal 4X100m team of 1996. "You have to go in with an open mind and be willing to learn."

That means checking your ego at the door and putting aside arguments over who should take on the anchor leg, which is usually the role that gets the most attention, but not necessarily more important than any of the others. As CBC track analyst Geoff Gowan puts it, "There's no glory in being the anchor if the entire team doesn't perform."

Like any team sport, the athletes in a relay play positions, and they have to understand those positions.

The best starter -- the one who isn't prone to false starts, and who can corner and make a clean baton exchange -- runs the first leg. The second runner has to be a strong, straight runner and has to be good at both passing and receiving. Ditto for the third runner, who also has to be able to corner well. As for the anchor, that runner must keep a cool head and not leave early, even if there's ground to be made up.

Since the top podium spot is reserved for the team that gets the baton from start to finish first (not the team with the fastest runners), the baton exchanges are even more important than pure speed.