If NBA fans around the country played word association with “Memphis Grizzlies” and “rivalry,” they’d probably see images of Zach Randolph and Blake Griffin rolling around on the floor. But while the recent battles between the Grizzlies and Los Angeles Clippers have generated more heat, the rivalry with the Oklahoma City Thunder has proven more momentous to Memphis.

On Thursday night, at Memphis' FedExForum, these teams will play for the 30th time in four seasons, including in three playoff series (counting this one). The Grizzlies hold a 15-14 edge, but the clashes have provided much more than that. The series has given Grizzlies fans six overtime games and the franchise’s first Game 7, and has paved the way for a first trip to the Western Conference finals.

Most of the lexicon of Grizzlies fan culture also has emanated in opposition to OKC: The boast-as-threat “We Don’t Bluff” traces to an altercation between Randolph and Kendrick Perkins in November 2012. The crunch-time penchant for converting “growl towels” into "Norma Rae"-style signs materialized organically during a Game 3 comeback against the Thunder in May 2011. Even “grit and grind” first came about on the sidelines of Chesapeake Energy Arena in February 2011. When Rudy Gay was traded, the team’s next game -- a loss, the “champagne taste on a beer budget" game -- was against the Thunder. When Marc Gasol unexpectedly returned from injury this season, in a win, it was against the Thunder.

If the Grizzlies-Clippers rivalry is embodied in Randolph vs. Griffin -- a prizefight of relative equals, made more compelling by their radically contrasting styles and personalities -- then the Grizzlies-Thunder rivalry is embodied in Tony Allen vs. Kevin Durant: an ostensible mismatch, the role player and the MVP, David and Goliath.

Last season, Allen was suddenly deemed too short for the assignment despite ample evidence to the contrary. He was kept off Durant for the first seven quarters of the teams’ second-round series, in which the Grizzlies lost one game and were headed toward losing a second. Finally let loose in the fourth quarter of Game 2, Allen held Durant scoreless for 7 minutes in a close win, stealing the ball for a meaningless-to-most exclamation dunk in the final seconds and then running by the scorer’s table, yelling, “First team, all-defense!”

Was he taunting his opponent? More likely speaking to some mixture of the basketball gods, himself and his coach. The Grizzlies swept the remaining games against the Thunder, with Durant increasingly overburdened.

This season, upon returning from injury, Allen reluctantly moved to a reserve role and averaged fewer minutes per game than increasingly limited starter Tayshaun Prince. But against the league’s most dominant scorer on Monday night, Allen played 35 minutes, while Prince played only 14. The Grizzlies won 111-105 in overtime to tie the series. As they say in Memphis, No. 9 when you need him.

Allen’s first couple of months with the Grizzlies didn’t go well, either. When he first came to the team, in 2010-11, he played behind rookie Xavier Henry and totaled nearly a dozen DNPs. He blackened the eye of teammate O.J. Mayo in a squabble over a card game. The first game after that incident was at home against the Thunder, and Allen spent the first quarter botching uncontested layups and suffering ballhandling misadventures. He ended it with 16 second-half points, a clutch 3-pointer (followed by a backpedaling shimmy), a violent block on a Russell Westbrook layup attempt, and several thousand new fans.

In Memphis, this became known as “The Tony Allen Game.” A February rematch that season in Oklahoma City, in which Allen had 27 points (still his high with the Grizzlies), 5 steals, 3 blocks, zero turnovers and brilliant late-game defense on Durant, rendered it “The First Tony Allen Game.” Following the overtime win Monday, Allen turned a postgame interview into an impromptu sideline soliloquy, warning of the dangers of the Ibakas and Sefoloshas of the world, but not before a now-familiar rallying cry: “It’s all heart. Grit. Grind.”

Oklahoma City brings out the best in Tony Allen. And now here he is again, matched up against arguably the best player of the 2013-14 season.

Grizzlies fans can work up a feverish, fun “sports hate” for Griffin and Chris Paul. Maybe even for smirking Westbrook or frowning Perkins or old-and-in-the-way Derek Fisher. But Durant? Not a chance. Grizzlies fans by and large don’t -- can’t -- dislike Durant. They regard him with a mix of awe and admiration, fear and resentment.

Tony Allen has come off the bench to find himself in a familiar role: locked up with Kevin Durant. Ronald Martinez/Getty Images

Instead, Durant’s greatness creates more of a sour taste. Memphis has never had a player like Durant, perhaps never will. Yet for Thunder fans, Durant is all they have ever known. Grizzlies fans (and the players they love most) often feel as if they’ve come up the hard way. They think Thunder fans have had it too easy.

The fan cultures also seem so different in these small, middle-American markets.

Oklahoma City’s crowd acts more orderly. Everyone dutifully puts on their themed T-shirts, bearing sincere, agency-sublimating slogans.

Memphis’ crowd seems more unruly. The Grizzlies used to try T-shirts come playoff time -- the “whiteouts” and “blue-outs” and what have you -- but had to spend too much time before games shaming reluctant fans into putting them on. The lockstep look didn’t fit, especially with unofficial Tony Allen T-shirts erupting into a local cottage industry. People preferred the towels. They lend themselves to more boisterous, physical expression.

It’s easy to be snarky from a distance, of course. To roll your eyes in the abstract. But Grizzlies fans who make the trip to Oklahoma City inevitably come back impressed by the intensity and the dedication Thunder fans have for their team, by the family atmosphere at games, and by the graciousness bestowed upon guests.

These are two great fan bases. But they are different.

And if Durant and Allen embody their teams -- the gifted favorite and the scrapping underdog -- they’re also perhaps fitting reflections of their communities.

Allen might not make sense as a cult hero in every NBA city, but he fits in colorful, big-hearted but rough-edged Memphis, where he’s embraced his “The Grindfather” persona so fully that he displays the nickname on a vanity plate on the front of one of his cars.

Durant’s persona, of course, would play anywhere. But more befitting pious, respectful Oklahoma City, Durant has declined the similarly fun and intimidating moniker “Slim Reaper,” asking instead to be called “The Servant.”

Now it’s back to Memphis, with Allen’s team holding home-court advantage and his matchup with Durant squarely in the spotlight. In what has become one of the NBA’s most compelling rivalries, the best is yet to come.

Chris Herrington is an entertainment editor and NBA contributor for the Memphis Commercial Appeal. Follow him, @HerringtonNBA.