In those 23 years, he has called nearly 400 tournament games.
"The one that stands out for me is the Gordon Hayward half-court heave against Duke in 2010," Nantz said.
"It was the ultimate Cinderella story. Butler, a mid-major, lo and behold, playing in the championship game in its hometown."
That what-might-have-been moment featuring a then-future Utah Jazz player, called by a former Utah Jazz broadcaster, is just one of dozens hundreds that have turned the NCAA Tournament into one of the premiere sporting events in America. And the folks at CBS aren't going to wait until March to look back on the madness.
Beginning Saturday, CBS Sports, the CBS Sports Network and CBSSports.com will feature a series of specials looking back at the tournament.
Up first is "75 Years of March Madness: Behind the Mic" (Saturday, noon, CBS/Ch. 2), hosted by Greg Gumbel and featuring a group of sportscasters including Nantz. Then Nantz hosts "75 Years: A Coach's Perspective" (Saturday, 1 p.m., CBS/Ch. 2), as Billy Donovan, Tom Izzo, Steve Lavin, Rick Pitino and others recall the top moments in tournament history.
For Nantz, who joined CBS' team three years after North Carolina State's buzzer-beating win over Houston in the final, his top moment remains the one that almost was. With 3.6 seconds remaining and Duke up 61-59, Hayward grabbed the rebound on a missed Blue Devil free throw, raced to midcourt and fired off a near miracle.
"Gordon launched the shot directly in front of us. He was so close, I could have almost stuck my foot out and tripped him if I really wanted to influence that game," Nantz said with a laugh. "When it left his hands, I could tell it was going to be close even though it was 47 feet away."
Almost three years later, the former KSL sportscaster still wonders how he would have called it had it gone in.
"As I've reflected on it, had that shot dropped, where would that have ranked?" he said. "Certainly, it would have been the biggest finish in the history of the NCAA championship. And then you start to take it another step is there another basketball moment anywhere that could ever compare?"
Jerry West made a half-court shot to send Game 3 of the 1970 NBA Finals into overtime, but it wasn't Game 7. And the Lakers lost that game and the series to the Knicks.
And Nantz believes that if Hayward's shot had gone in, it would have eclipsed great moments in major golf tournaments, Super Bowls and World Series. Sure, Kirk Gibson hit a walk-off home run to win Game 1 of the 1988 World Series for the Dodgers, "But guys hit home runs. It's not unusual to see a walk-off home run," Nantz said. "But a half-court heave?
"Gordon Hayward of the Utah Jazz was an eighth of an inch away from delivering the greatest finish in the history of sport. That's what I think."
Scott D. Pierce covers television for The Salt Lake Tribune. Email him at firstname.lastname@example.org; follow him on Twitter @ScottDPierce.