PROVIDENCE, R.I. — Rick Pitino has matched wits with Mike Krzyzewski and Dean Smith, with John Thompson and Jim Boeheim, with Roy Williams, Lute Olson and more, but the only coach he has seen as a true rival — a “disliking-each-other rival,” in his words — is Jim Calhoun, a bitter nemesis during Pitino’s stints at Boston University and Providence.

When Calhoun was at Northeastern, the Terriers’ crosstown adversary, the two would shoot daggers at one another in front of crowds numbering in the hundreds, Pitino recalled. This rancor continued when the pair migrated to the Big East, with Pitino taking both matchups during the 1986-87 Friars’ magical run to the Final Four.

“We hated each other at BU and Providence, hated each other,” Pitino said. “He goes on to coach at Connecticut, I go on to coach at Providence, and we hated each other there, as well.”

His relationship with Arkansas coach John Calipari is different, surprisingly, given the toe-to-toe battles during overlapping tenures at Louisville and Kentucky that often served as a referendum on regional and national supremacy.

Not good friends but not enemies, either, the Pitino and Calipari dynamic can be described as unenthusiastically respectful: not bitter or unkind but lacking the warmth and camaraderie that come with many connections in the coaching fraternity.

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“I have always had great respect for John,” Pitino said. “You know, I certainly have great respect for him, but we’re not really close. Everybody tried to talk that way. It was just a Kentucky-Louisville and Louisville-Memphis thing. We don’t know each other’s wives or children. We’re not really close friends.”

Said Calipari, “I don’t know how long he was at Louisville when I was at Kentucky, but you’re not going to be friends when you got those two jobs. You’re not going to be enemies, but if he’s real good, you’re like, sheesh, and if we were real good, he’s probably saying, ugh.”

Even if not rooted in the same venom that shaped Pitino’s rivalry with Calhoun, this coaching matchup is a TV-ready, must-watch coupling of two coaches who continue to occupy a special place in the college basketball ecosystem: Pitino against Calipari moves the needle as much as any coaching contest the sport can provide.

They’ll meet again in Saturday’s second-round NCAA Tournament matchup pitting No. 2 St. John’s against the No. 10 Razorbacks, the 30th iteration in a series that has included four previous postseason contests. Two of those came in the Final Four: Pitino and Kentucky got the better of Calipari and Massachusetts in 1996, while Calipari and the Wildcats returned the favor against Louisville in 2012.

Counting six games in the NBA, Calipari owns a 16-13 edge in head-to-head meetings against Pitino. The most recent came on Dec. 16, 2016, when the Cardinals beat the Wildcats 73-70.

“I will study what he’s doing,” Calipari said of Pitino. “I always do. Watch what he’s doing, how he’s doing it.”

Asked where he and Pitino find common ground and where they diverge, Calipari said they “both have big noses, so that’s one.” But Pitino has “Gucci shoes and I have itchy shoes, so we’re different there.”

Pitino pushed back on the idea that there’s anything personal involved in Saturday’s game, saying he was solely concentrated on the on-court matchups between his Big East champions and an opponent that pieced together a 79-72 win against No. 7 Kansas in the opening round.

“I don’t go against coaches; we go against teams,” he said. “He doesn’t have to worry about me. My jump shot is long gone. We’re preparing for his players. He’s preparing for our players. John and I don’t play one-on-one anymore.”

Saturday’s game features two programs at different stages of rebuilding. Pitino called last year, his first with the Red Storm, “the most unenjoyable experience” of his career. But this season has seen St. John’s take home an outright regular-season league championship for the first time since 1985 and win 30 games for the first time since 1986. St. John’s opened the tournament by beating No. 15 Nebraska-Omaha 83-53, pulling away after a sluggish first half.

Calipari’s own debut after 15 years at Kentucky has gone slightly better. After starting 0-5 in SEC play, the Razorbacks rallied in the second half of the conference season to secure a tournament berth. Whether the program can follow the Red Storm’s lead and make a second-year surge remains to be seen.

“He’s on chapter two of his new book and we’re on chapter one,” said Calipari. “As a matter of fact, we’re probably on the first few pages of the chapter. It’s both of us writing another story and being able to come back here.”

The addresses may change — Amherst, Lexington, Louisville, Fayetteville, Queens — but certain coaching styles do not, both coaches said this week.

“We know what we’re up against, obviously,” said Pitino.

Like Pitino-coached teams he’s faced in the past, Calipari said playing the Red Storm is “like you’re in combat.” St. John’s is going to make you earn everything, he told the Razorbacks.

“They’re a team that’s going to play prepared. They’re going to play hard. They’re going to play rough. It’s going to be bump and grind. You’re not getting a free layup without getting bumped.”

Arkansas is “very long, athletic,” Pitino said, and more dangerous for having a deeper rotation following the return of freshman guard Boogie Fland. He suffered what was expected to be a season-ending hand injury in January, when he was averaging 15.1 points, 5.7 assists and 3.4 rebounds per game, but played a critical role across 24 minutes of action against the Jayhawks.

“We have not seen this size and athleticism all year,” said Pitino. “Most of his teams are extremely athletic. This team is as athletic as I have seen. This team is quite extraordinary.”

Personnel, not personality, will decide which team heads to the second weekend. But it’s inevitable that Saturday will bring the focus back to the matchup between two coaches linked by success and late-career second acts that has led to yet another high-stakes game.

“We’re all going to be judged 50 years from now on what we did and how we did it, but I hope years from now people will say they both got their teams to play hard at a competitive level,” said Calipari.

“Do we do it different? Yeah, I guess. I am who I am. Like it or not, this is how I am and how I deal with kids. We’re all different with that.”