John grew up in an affluent suburb playing baseball and football as a boy. He did not play organized soccer as a boy. He learned the game in grade school in pick-up games during recess. But by the time John enrolled in Chatham High School, he had the basic skills needed to master the sport. Otto Haas, who’d been coaching the team since the 1940s, put the finishing touches on John's game.
Unlike most New Jersey high schools, the glamor sport at Chatham was soccer, and John was the superstar of the team. He averaged close to a goal a match during his varsity career, including 30 in 15 games as a senior in 1961.
John enrolled at Temple University in 1962. He played varsity baseball, tennis and soccer. He played in 36 games for the Owls soccer team before a knee injury ended his career. After graduation, John focused on a career in education. He taught social studies in Bergen and Middlesex County schools. In the early 1970s, coach Haas began encouraging him to coach college soccer. He helped him land a job at the University of Southeastern Massachusetts in 1972 and a year later he was coaching closer to home, at Columbia University. He turned one of the country’s worst teams around, earning a berth in the NCAA Tournament in 1978.
The following season, John was hired to coach at Duke. The Blue Devils had a winning record in each of his first 22 seasons. In 1982, Duke made it to the NCAA Tournament final, losing 2–1 to Indiana. The game took 159 minutes—including 8 overtimes—the longest playoff soccer match in NCAA history. Joe Ulrich, winner of the Hermann trophy, committed the foul that gave the Hoosiers the free kick that won the game. John took some small measure of satisfaction when he was named National Coach of the Year.
In 1986, John guided Duke to the NCAA title. It was the first national championship in school history. The Blue Devils went 13–5–1 on the season but ran the table in the tournament, beating South Carolina, NC State, Loyola–Maryland and Harvard before edging Akron 1–0 in the final. Tom Stone scored the golden goal.
John's teams won five ACC titles—1980 and '82, 1999 and 2005 and 2005. He was ACC Coach of the Year 5 times. During his Duke coaching career, John coached 8 first-team All-Americans: Joe Ulrich, Mike Jeffries, Tom Kain, John Kerr, Brian Benedict, Joey Valenti, Jason Kreis, Jay Heaps and Al Curtis. John retired in 2007 with 454 wins, 207 losses and 48 ties as a college coach. In 2011, he was inducted into the North Carolina Soccer Hall of Fame along with MLS star Roy Lassiter and Tom Mosier. In 2013, John was inducted into the Duke Athletic Hall of Fame.