GREENSBORO, N.C. -- North Carolina coach Roy Williams made the move of the season.
Debate it all you want. But the decision by Williams to take junior Larry Drew II out of the lineup and insert Kendall Marshall into a starting position in mid-January changed the Tar Heels' season and the ACC -- and ultimately it could affect the national championship.
Williams gave Drew plenty of time to play the position after taking over for Ty Lawson following the 2008-09 national title season. He wasn't the only reason the Tar Heels failed to make the NCAA tournament last season, as they dealt with injuries (Ed Davis) and never could find any consistency on the perimeter.
Between Drew and Marshall, Drew was the better defender, according to one ACC head coach. And he was, at times, a more stable presence. But he wasn't the prototypical Williams-Carolina point guard for the Tar Heels' pass-ahead break offense.
Marshall wasn't that player at the beginning of the season, either.
"I had a lot of maturing to do,'' Marshall said. "I had to learn how to play hard every possession, and I had to become a better defender. Coach knew what he was doing because I wasn't ready to be out there and handle the position. I had to wait until it was my time.''
Williams said he had wanted to make the move a few games earlier, but Marshall was ineffective in a loss at Illinois on Nov. 30 (16 minutes, four turnovers). He then considered making the switch Dec. 4 against Kentucky. But again, Marshall didn't show much with three assists and three turnovers in 10 minutes.
"He had to start playing well in order to deserve it,'' Williams said.
The 20-point loss at Georgia Tech in mid-January was when things hit rock bottom. Williams knew he had to make a change to alter the direction of his team's season.
North Carolina has lost only two games since the Tech debacle -- both to Duke, one in Cameron and the other last Sunday in the ACC tournament title game.
And despite playing well, Drew II left the Tar Heels in early February.
Marshall had 16 assists and three turnovers in a win over Florida State on Feb. 6. He scored 18 points in a victory at Clemson, had 10 assists and four turnovers in a win versus Maryland and tallied 15 points, 11 assists and two turnovers in a win over Duke to close the regular season.
Of course, it hasn't been all about Marshall. Star freshman wing Harrison Barnes has emerged as a big-time performer. He made a 3-pointer to beat Miami on the road, hit a game-winning 3 at Florida State and then scored 40 in an overtime win over Clemson in the ACC semifinals.
And while the bench has been depleted with the injury to Reggie Bullock, there is no denying the numbers.
The Tar Heels are simply better with Marshall running the point. The bigs are happier on the break and in the post. Tyler Zeller was the recipient of Marshall's last-second feed for a game-winning layup against Miami in the ACC quarterfinals.
Marshall said Williams told him matter of fact that he would be starting against Clemson, two days after the loss at Georgia Tech.
"It just showed he had confidence in me,'' Marshall said. "I wouldn't say there was any pressure on me. We lost some vital parts to our team [in Drew II and Bullock], and that means the whole team has to step up. We became tighter. Justin Watts brought the team closer together. He was on that championship team and knew how they found ways to win games.''
The Georgia Tech loss turned out to be the wakeup call everyone needed.
"Larry had three years to do it,'' Barnes said. "Kendall had to step up big for us this year.''
Marshall's teammates have the utmost confidence in his ability to feed the post, knowing when to take a 3-pointer, run the break and get the ball to Barnes.
"He's a great point guard when he has weapons at his disposal,'' said John Henson. "He sets us up at the right position, and we have to finish it up for him. He might not have been ready earlier, but he was thrown into the fire and he's handled it really well.''
The Tar Heels, winners of the ACC regular-season title and a No. 2 seed in the NCAA tournament, have a real chance to make the Final Four in Houston.
"He just has to keep it simple,'' Williams said. "He's still learning. He has to know when to score and when to take chances and get shots for everyone.''
Marshall sought the advice of former Carolina point guards Ed Cota and Lawson. And the common refrain was to make sure that the Tar Heels get great shots every time down the court.
"It's tough being the point guard at Carolina,'' Marshall said. "It's like the Notre Dame or USC quarterback. Everyone talks about it.''
And as the team heads into Friday's second-round NCAA tournament game against No. 15 Long Island in Charlotte, there's reason for optimism -- thanks in large part to Marshall.
North Carolina was 12-5 and 2-1 in the ACC when the move was made. The Tar Heels finished 26-7 overall and 14-2 in the league.
And even if Carolina doesn't win the national championship, it will certainly go down as the move of the season because it helped ensure a high-major regular-season title.
Andy Katz is a senior writer at ESPN.com.