People who study such things say there are several factors that make for a good sports rivalry. Geographic proximity helps. Even better if each team has been highly successful in its own right. Better still if each team has won a number of games against the other. A series rich with emotional memories completes the picture.
"You have the perfect storm of a rivalry with Louisville and Kentucky," said Daniel L. Wann, a professor of psychology at Murray State University.
Of course, this annual storm re-forms and blows through the Yum Center on Saturday.
Art Markman, a professor of psychology and marketing at the University of Texas, likened a Kentucky-Louisville game to a family gathering to celebrate Christmas each year. The ironic idea is that Kentucky and Louisville are more alike than different as basketball entities: proud histories, national championships, All-Americans, enthusiastic fans.
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"The reason we do so many traditions each year is so we can feel close to who we were on that holiday in the past," Markman said. "The same thing happens with a rivalry. You're not only feeling the excitement of the game, but you're remembering what happened last year, what happened five years ago."
Markman even put the sniping that goes back and forth between Kentucky and Louisville fans in the same familial context.
"They are like cousins," he said of how the rival blue and red fandoms eye each other. "They are not unrelated. Inside the family, there is the good-natured teasing that goes on. You have to figure out what it takes to push the buttons of your rival."
Kentucky and Louisville long ago learned which buttons to push. Billy Reed, whose sportswriting career includes stints as a columnist for The Herald-Leader and The Courier-Journal, was there when the current series began in the 1983-84 season. He credits Denny Crum's arrival as Louisville coach in 1971 as the first stirrings of the rivalry-to-be.
"They were the first program in the state to actually challenge Kentucky's supremacy," Reed said.
Kentucky basketball, never too tired to take a bow (the public address announcer proclaims "the greatest tradition in the history of college basketball!!!" before each home game), does not get deference from Louisville. U of L fans even dare to mock UK. "That's going to definitely fuel the fire, without question," Wann said.
Lack of respect is a two-way street.
What bothers Louisville fans about Kentucky is a refusal to acknowledge what the Cards have done.
"No matter how hard they strive or how much they succeed across the board, the Kentucky fans will not accept them as equals," Reed said. "No matter how many straight football games they win, or whatever, there is just that air of superiority that Kentucky fans have toward Louisville."
Perhaps unwittingly, then-UK coach Eddie Sutton captured this superiority complex before the 1986 game when he famously referred to Kentucky as the "Big Brother" to Louisville's "Little Brother."
What Sutton seemed to be trying to say, however inartfully, was that Louisville had a rich and storied basketball history, just not as rich and storied as Kentucky's.
Former UK player Cameron Mills suggested that the Kentucky-Louisville divide cannot be bridged.
"We were raised to hate Louisville," he said. "That's how it works here. It's just the way it is."
Yet Markman used the word "wholesome" to describe sporting rivalries.
"It really is a kind of wholesome outlet for emotion and excitement," he said. "And a lot of times there is deep, deep down a kind of respect for your rival. Because, otherwise, why would you bother?"
Kentucky could never have a rivalry with, say, Princeton, Markman said. The basketball programs and universities are too dissimilar.
However, Wann noted a "darker side" to rivalries. The San Francisco Giants fan assaulted outside Dodger Stadium. The Alabama fan who poisoned trees at Auburn.
Kentucky-Louisville games have been relatively free of ugliness. The worst may be when someone threw a quarter that hit Crum at Rupp Arena in 1984.
But to read blogs and Internet message boards is to wonder if there's more anger in the world or simply more means to express anger.
Wann does not wonder.
"There's more anger," he said. "Studies show that empathy has gone down the past five decades."
Then, as if he just thought of it, Wann added, "You know what we don't hear: The phrase 'friendly rivalry.' No one says that anymore.
"There's almost no such thing as a friendly rivalry because people aren't as nice and civil as they once were. They take these things pretty much to heart."