To understand what drives a rivalry, just take a look at what comes between the two rivals. Jay Leno and David Letterman battle over the night, while Republicans and Democrats duel for a better tomorrow. Harvard and Yale clash over which school has a bigger thirst for knowledge, as Coke and Pepsi tussle for the biggest knowledge of thirst.
At its core, a true rivalry is about the prize as much as the participants.
Take the Chicago Cubs and St. Louis Cardinals. All that stands between these two adversaries is a mere 297 miles of rich, Midwestern soil. With each team intent on owning that land, this rivalry is really a turf war.
"The first time I played in a Cubs-Cardinals game," said former Cardinals player and current Angels broadcaster Rex Hudler, "I couldn't believe what I was seeing.
"The crowd was 50/50 -- half for the Cardinals and half for the Cubs. The place was packed during batting practice. The atmosphere was unbelievable."
As Hudler walked through the tunnel and into the rivalry for the first time back in 1990, he had one question for teammate Ozzie Smith: "What is this, the World Series?"
"Welcome," Smith replied, "to the Cubs-Cardinals rivalry."
The proximity between the two cities means that wherever and whenever the teams meet half of the fans in attendance are standing their ground while the other half encroaches upon it.
"Whenever the games are played, Wrigley Field or Busch Stadium, it's always packed," said Cubs play-by-play announcer Len Kasper. "If the fans aren't wearing Cardinals red, they're donning Cubs blue."
Political pundit George Will grew up halfway between the two cities, in Champaign, Ill., and has said the biggest decision of his life was whether to back the Cubs or the Cardinals. Will opted to for Cubs blue, and he has said the decision shaped his life.
"While all my friends were becoming Cardinals fans," Will said in 1998, "I became a Cub fan. My friends, happily rooting for Stan Musial, Red Schoendienst and other great Redbirds, grew up cheerfully convinced that the world is a benign place, so, of course, they became liberals. Rooting for the Cubs in the late 1940s and early 1950s, I became gloomy, pessimistic, morose, dyspeptic and conservative."
In addition to being powerful enough to shape political viewpoints, the Cubs-Cards rivalry also is a battle for Midwest supremacy.
"The cities are so close that it was only natural for such a passionate regional rivalry to develop," said Jay Johnstone, who played for the Cubs from 1982-84.
Midwestern bragging rights hang in the balance, and maybe that's why the rivalry has an undercurrent of civility to it. People in the Midwest just aren't prone to bragging much.
The teams' battle for control of the Midwest is not always fought on the field, as the two organizations have gone high-tech in their efforts to annex the territory between St. Louis and Chicago. For years, the Cardinals' games were heard throughout the Midwest on 50,000-watt radio giant KMOX, while the Cubs were broadcast on 50,000-watt WGN.
Ultimately, the Cubs won the media war when they began televising virtually all of their games nationally on a superstation in 1980s. In the process, lovable losers became a beloved national franchise. Today, the majority of Cubs games are available nationally on a series of networks.
The Cardinals may carry a much lower profile on the national scene, but with 10 World Series titles there's no inferiority complex in the Gateway City.