Bill Parcells retired yesterday from the Dallas Cowboys, concluding a tumultuous four years for the future Hall of Fame coach. Along with his tenure in Dallas, his nomadic career has included stops with the Jets and the New England Patriots, but he has never matched the success he had in his first job with the Giants.

“I am retiring from coaching football,” Parcells said. But with his history of announcing his retirement only to turn up on the sidelines again, it’s hard to believe we’ve seen the last of Parcells, whose career has been marked not only by success at all four of its stops, but also by a constant search for new opportunities.

Parcells was promoted from the Giants’ defensive coordinator to head coach in 1983, when Big Blue was one of the league’s worst franchises, with just one winning season in the previous 10 years. Although the Giants went 3–12–1 in his first year, Parcells spent that season weeding out the players who didn’t buy into his system. The Giants improved dramatically in 1984 and were one of the best teams in football for the rest of the decade, winning the Super Bowl in 1986 and again in 1990.

Turning around moribund franchises would become the defining characteristic of Parcells’s career. Parcells left the Giants after the 1990 Super Bowl season and spent two seasons working in television, but getting back into coaching was never far from his mind: He came close to accepting a deal in 1992 to coach the Tampa Bay Buccaneers, then agreed in 1993 to coach the New England Patriots. The Patriots went 2–14 the season before Parcells arrived, but by 1996 he had them in the Super Bowl.

After that, Parcells left New England to coach the Jets. The Patriots said Parcells had no right to leave while still under contract, and commissioner Paul Tagliabue negotiated a settlement that allowed Parcells to coach the Jets but forced them to compensate the Patriots. Parcells was worth the price and then some: In the two seasons prior to Parcells’s arrival, Rich Kotite led the Jets to a combined record of 4–28. In Parcells’s first season, the Jets went 9–7, and in his second season they went 12–4 and made it to the AFC Championship game.

Parcells’s third and final year with the Jets got off to a disastrous start when quarterback Vinny Testaverde ruptured his Achilles’ tendon in the opener, and the Jets finished a disappointing 8–8. At the end of that season, Parcells announced his retirement as coach (he stayed one more year as general manager) and insisted he was done for good: “Bill’s not coming back,” Parcells said in January 2000. “You can write that on your chalkboard.”

But virtually nothing Parcells said the day he retired from the Jets turned out to be true — Parcells also announced at the time that his longtime assistant Bill Belichick would replace him as the Jets’ head coach. The next day, Belichick announced that he would leave the Jets and coach the Patriots. Three years later, Parcells was coaching the Cowboys. Although the Cowboys made the playoffs only twice in Parcells’s four years and lost in the first round both times, Dallas is vastly improved from the 5–11 club Parcells inherited.

Even if Parcells really has retired from coaching for good, several teams would likely be interested in having him work in their front offices. Just last week Parcells denied reports that he was interested in becoming the Giants’ general manager. Rumors like that will continue to surface, and Parcells still has ties to both local teams: Jets general manager Mike Tannenbaum and Giants head coach Tom Coughlin have both worked for Parcells, and although he’s unlikely to run either team’s front office, he could work as a consultant. He could also become a college coach — he spent one year as head coach at Air Force in 1978 and was rumored to be interested in the University of Kentucky job as recently as five years ago.

But given his history, there’s no reason to think Parcells won’t return to doing what he has done for so long, coaching an NFL team. His statement that he is retiring from coaching football aside, if the right situation arises, the 65-year-old Parcells will have at least one more stint as an NFL coach.

Mr. Smith is a writer for FootballOutsiders.com.