From the time they met, John Carroll was trying to explain his affinity for the 3-point shot to Laurent Rivard.

In Carroll’s playing days, he never quite understood it.

The paint always seemed like a moshpit — all the fighting for rebounds, muscling up shots, ugly collisions at the rim, turf wars on the block.

Basketball in the free throw lane was messy business.

But life was different at the 3-point line. There was room to breathe. He was on his own island with his defender. He had a nice view of the basket, nice enough to knock down any shot he wanted from long range.

And those shots were worth more.

“My philosophy as a player was those kids really have to work hard for 2 points,” Carroll said. “To stand out there and shoot 3s is not as much work. You know, one and one equals two, but one and two equals three. That also made sense to Rivard, too.

So Carroll went with what made sense. At Assumption College, he fired deep ball after deep ball until his 342 3-pointers set the school record.

“I spent a lot of time shooting,” Carroll said.

When he became head coach of his alma mater, Northfield Mount Hermon, hitting opponents with 3-point rainstorms wasn’t just a strategy, it became a culture.

Northfield Mount Hermon rolled sharpshooters off the assembly line, from Aaron Cosby at Illinois to Mike Marra at Louisville, whom Rick Pitino once called, “the greatest high school shooter I’ve ever seen.”

But Rivard was a special breed.

He thought about shooting in a completely different way, Carroll said. It wasn’t a skill, it was a science.

“He’s a computer programmer,” Carroll said. “He has that kind of mind where the science of shooting made sense to him. Once he realized that it was something that if he really worked on — based on the amount of hours you put in — you get results. That’s the kind of thing that really made sense to Laurent.”

Growing up in Quebec, Rivard was the one in the moshpit. Most of the points he scored came with bruises. But as he got older, he moved further away from the basket. Under Carroll at NMH, he began the transformation that would turn him into the long-range sniper who would go on to be Harvard’s all-time leader in 3-pointers.

“He kind of liked that so he took me under his wing and it gave me a lot of confidence,” Rivard said. “I think that’s pretty much the best thing a coach can do for a player — just have a lot of confidence in him and in return I get a lot of confidence in myself.”

For Carroll, Rivard’s work ethic made him the ideal pupil.

“It’s easy to find guys that want to learn how to shoot,” Carroll said. “But Laurent is in an elite category. Any time you get a kid that works at the level that he works at, if you give him a task with an immediate and deliberate response, he loves it. So I think it was a good marriage as far as philosophy and shooting and his desire to work.”

Looking back on Rivard’s four years at Harvard, none of it was guaranteed.

Not the four straight Ivy League titles. Not the three straight trips to the NCAA Tournament. Not the 282 3-pointers Rivard has knocked down to put him second all-time on the Ivy League list. Not the five treys he drained a year ago that sealed Harvard’s first ever NCAA Tournament win. Not the chance to do it again Thursday when 12th-seeded Harvard faces fifth-seeded Cincinnati in the opening round of the tournament.

Harvard coach Tommy Amaker laid out all those possibilities for Rivard when he went to NMH to recruit him, but the Crimson were still a team trying to create something from the ground up.

Amaker had a clear vision for Rivard. He saw exactly how the guard’s shooting would fit.

“He’s always been known as a tremendous shooter,” Amaker said. “That was his strength. I think the things that we found and fell in love with just as much as that was that he’s tough. He’s a tough-minded, rugged kid. He’s not afraid of taking a big shot. He’s not afraid of putting his body on the line.