The Birth of the Arc

The Birth of the Arc

The morning of October 12, 1979, arrived with the kind of crisp autumn chill that settles over Boston in early fall. At the team facility that would later become known as the New England Sports Complex, a group of professional basketball players gathered to prepare for the most significant rule change the game had seen in decades. Most of them were ambivalent about it. Some were outright dismissive. None of them—players, coaches, executives, or league officials—could have predicted what this particular morning would ultimately mean for the sport they loved.

Chris Ford arrived early, as was his custom. At twenty-nine years old, the Boston Celtics forward had already carved out a reputation as one of the league's more thoughtful players, a student of the game who approached basketball with the analytical mind of an engineer—which he had been trained to become before his body convinced him that professional athletics might be a viable alternative. Ford had played his college ball at the University of Notre Dame, where he had studied aerospace engineering, and that methodical approach to problem-solving had followed him onto the court. He understood angles, trajectories, and the physics of motion in ways that many of his contemporaries did not. He was, in the parlance of the era, a "thinking man's player"—which in the late 1970s could sometimes be a backhanded compliment.

On this particular morning, Ford was about to become the answer to a trivia question that would persist for the next forty-five years and counting.

The rule that had brought everyone to the gym early, that had dominated preseason conversations and team meetings, was the introduction of the three-point line to the National Basketball Association. After years of experimentation in the American Basketball Association and a growing consensus among league executives that the game needed more scoring, more excitement, and more strategic variety, the NBA had finally adopted what the ABA had been testing since 1967. Starting with the 1979-80 season, any basket made from beyond a designated arc—twenty-three feet, nine inches at the top of the key, extending to twenty-two feet at the corners—would count for three points rather than two. Simple in concept. Revolutionary in execution. Terrifying in implication for players who had spent their entire careers optimizing for a different geometry of the court.

The Shape of the Game

To understand why the three-point line seemed so radical in 1979, one must first understand what professional basketball had looked like without it. The pre-three-point era was characterized by what coaches euphemistically called "good shot selection"—which meant shots from immediately inside the free throw line, or the immediate vicinity of the basket. The further from the hoop, the lower the expected value of a shot. A layup was worth nearly 1.8 points per attempt. A mid-range jumper from fifteen feet might generate 0.9 points per possession. A long two-pointer from beyond eighteen feet, the kind of shot that became almost laughably obsolete in the decades to come, might produce only 0.7 points per attempt. The mathematics were brutal and unforgiving.

Coaches, therefore, invested enormous resources in what they called "ball movement" and "player movement"—elaborate systems designed to create the appearance of chaos while actually engineering precise geometric arrangements that would yield high-percentage shots. The Boston Celtics under Tommy Heinsohn. The Philadelphia 76ers under Billy Cunningham. The Los Angeles Lakers under Paul Westhead, before Pat Riley would eventually reshape the franchise's identity. Each system was built on the same fundamental principle: get the ball as close to the basket as possible, as often as possible, and good things would follow.

The three-point line threatened to upend this entire philosophy. If a shot from twenty-four feet was worth fifty percent more than a shot from twelve feet, why wouldn't teams simply launch more long-range attempts? The conventional wisdom said this would be madness—that young players who took "bad shots" would be riding the bench, that coaches who permitted such foolishness would be looking for new employment, that the mathematics of the game simply did not support such profligacy.

Yet the ABA had been experimenting with this radical notion for twelve years, and the results had been intriguing. In the ABA's final season of 1975-76, the league that would merge with the NBA had seen more than double the three-point attempts per game than the NBA would record in its own inaugural season with the line. The style of play was different, faster, more aesthetically pleasing to some observers. The problem was that the ABA had also been hemorrhaging money, and many NBA owners blamed the three-point line—rather than the ABA's general financial mismanagement and the recession that had battered the country—for the smaller league's struggles.

When the merger was finalized in 1976, the three-point line was one of the most contentious issues on the negotiating table. The NBA owners ultimately voted to adopt it, but with a compromise that would define the shot's early years: the arc would be positioned differently than it had been in the ABA, creating what statisticians would later identify as an objectively inferior shooting geometry. The corners were closer to the basket than the top of the key. The corners were, therefore, mathematically optimal—though it would take nearly two decades for teams to fully exploit this reality.

The First Shot

Chris Ford did not know, on that October morning in 1979, that he was about to make history. History, in his experience, was something that happened to other people—to Bill Russell and Wilt Chamberlain, to John Havlicek and Dave Cowens, to the legendary figures who had shaped the Celtics' glorious past. Ford was a solid, reliable rotation player, a defensive specialist who could also knock down an open jumper when the opportunity presented itself. He was not, in his own estimation, the kind of player who would be remembered for changing the game.

What he did know was that his team was preparing for a preseason game against the Houston Oilers—a name that would later be changed to the Rockets after the company withdrew its sponsorship—and that the coaching staff had emphasized the importance of understanding the new three-point geometry. Coach Bill Fitch, one of the most demanding and analytically sophisticated minds in the game, had made it clear that he expected his players to adapt to the new rule immediately. Fitch had spent the summer studying the rule's implications, examining how it would change defensive rotations, offensive spacing, and the fundamental calculus of when and where to shoot.

"He was ahead of his time in understanding how the game would evolve," Ford would later recall in interviews. "Fitch knew that the three-point line was going to change everything. He just wasn't sure exactly how, and he wanted us prepared for whatever came."

The moment arrived during the second quarter of the October 12 exhibition game. The Celtics were running a play designed to create space for their perimeter players—a basic continuity offense that Ford had executed hundreds of times in practice and games. The ball moved quickly, as Celtics offenses always did in the Fitch era, and when it found Ford on the left wing, he had a clear look at the basket. He was standing just beyond the newly painted arc, perhaps twenty-three feet from the hoop, in a position that would have yielded a meaningless long two-pointer in any previous season. But this was a new season, with a new rule, and Ford understood instinctively what that meant.

He released the shot with the same form he had used for thousands of practice jumpers. High arc. Quick rotation. Follow-through toward the target. The ball sailed through the air in a perfect parabola, spun gently end over end, a