On Thursday, they demonstrated why they're so good. They stay loose.
Instead of getting tense and out of sorts the day before the Midwest Regional's well-hyped coaching matchup, the pair took turns praising one another's styles, their loyalty to their schools and their teams' penchant for limiting mistakes. Then they turned around and poked fun at themselves and their families. It was basketball at its most polite.
"I consider him a great friend. There's nothing about Tom that I don't think is good. If we lose to them, believe me, I'll hug him and shake his hand, and he'll do the same for me. I like that," said Krzyzewski, the NCAA Division I record-holder with 956 career wins. "I think it's more the way it used to be in coaching, and probably we both have great teachers in that regard and were brought up a certain way where we understand the game is bigger than anybody."
Even heading into a game that will put one of these coaches within a victory of yet another Final Four trip.
There may not be a more compelling coaching duel in this year's tournament.
In 33 seasons at Duke, Krzyzewski has gone to 11 Final Fours, the most among active coaches. He is one of only three coaches in NCAA history to win at least four national championships, two of those coming in Indy. The last time he faced Michigan State, the Blue Devils gave him a 74-69 win that broke Bob Knight's career record for wins. Izzo doesn't mind playing that role.
"I'm going to be famous someday because it was our game last year at New York that broke the record, and I guess if you've got to be famous, who cares what the reason is," Izzo said, drawing laughter. "Yet, I look at it too that if we had to lose to somebody that was doing something special, the class and the way he's done things over time, his staff, his recruiting, we've had to recruit against him a few times and it's always fair and up and up. We usually lose, but we're trying to make some progress."
Izzo's done a pretty darn good job in his own right. He owns a school-record 439 career wins in 18 seasons at Michigan State and won his only national title in 2000, also in Indy.
But as two of the longest-tenured and most successful college coaches, each has their own distinct style.
Izzo has, at times over the past week, taken away players' cell phones to improve communication within the team and help them focus. Krzyzewski has not.
Izzo prefers hearing the chatter on the team bus, while Krzyzewski seems more inclined to concentrate on game plans.
And while Krzyzewski only occasionally pumps a fist or screams, Izzo never hesitates to show his passion.
"My favorite story was my freshman year when I got a dunk at Purdue and I missed it. I hung on the rim and grabbed the ball as it came off and dunked it again," forward Derrick Nix said. "I got called for a technical for hanging on the rim, and when I came over, coach Izzo asked me if I thought I was playing in the city league."
It's enough to make anyone, including Nix, laugh.
Both come into the game focused first on defense, though Duke (29-5) has been slightly more proficient on offense and Michigan State (27-8) slightly more physical. Both can rely on their high-scoring big men -- Mason Plumlee and Ryan Kelly for the Blue Devils and Nix and Adreian Payne for the Spartans -- to carry them. And both have been contended with injuries to key players who say they hope will be at or close to 100 percent Friday.
Kelly missed 13 games earlier this season with a right foot injury but has played well since returning and appeared to be having fun as his teammates closed their 50-minute open practice with a pseudo-dunk contest.
Keith Appling wore a brace over his injured right shoulder during the Spartans' open workout, and like his teammates, appeared to be at ease as Izzo roamed the court, shouted instructions and shook hands with the people he knew before their dunk contest.
"I wouldn't really say that my shoulder is 100 percent, but it's close to it," Appling said. "I'm going to do as much as I possibly can to help my team advance in this tournament."
But what most people will be watching Friday night is the strategy coming from the sidelines.
"I'm going to enjoy it because it's like a Final Four game. It might be better than a Final Four game," former Virginia and Xavier coach Pete Gillen said. "I'd pay to see this one and I'm tight as a clam."
Even though Krzyzewski and Izzo would prefer to talk about anything other than their opposing coach.
"It's not going to be a chess match. That's putting the coaches too much involved here," Krzyzewski said. "We'll both have our teams prepared to play against one another, and you can't be instinctively reactive to what's going on in the game if you're constantly looking at your coach to tell you every move."