Mavety returned to Denver for the 1970–71 season, and finished second in team scoring with 63 points (18G-45A) in 71 games as the Spurs qualified for the playoffs.
He returned to the Cougars for the 1973–74 season, registering 51 points (15G-36A) in 77 games and helped the club make the post-season.
In 1979–80, Mavety was hired by the Belleville Bulls, an expansion junior tier II team in the OHA.
In 1980–81, he led the Bulls to a 35–7–2 record, as the team won the league championship, defeating the Guelph Platers.
The Bulls then went on to play for the national championship for the Manitoba Centennial Trophy, losing to the Prince Albert Raiders in the final game.
In 1981–82, the Bulls moved to the Ontario Hockey League (OHL) as an expansion team, where they finished the year with a 24–42–2 record, and missed the playoffs.
In 1982–83, the Bulls improved to a 34–36–0 record and qualified for the playoffs for the first time, as the club lost to the Oshawa Generals in the first round.
The Fronts had a disappointing playoff though, losing in seven games in the opening round to Mavety's former team, the Belleville Bulls.
For the 1990–91 season, Mavety returned to coach the Bulls, who finished with a 38–21–7 record, and lost to the Ottawa 67's in the first round of the playoffs.
Kingston struggled to a 22-42-4 record during the 1998-99 season, however, the club reached the post-season in the eighth seed in the Eastern Conference.
The stellar goaltending from Raycroft helped the Frontenacs to an impressive 38-22-5-3 record during the 1999-2000 season, as the club finished in fifth place in the Eastern Conference.
The club earned their fourth consecutive playoff berth since Mavety returned, however, Kingston was swept in the Eastern Conference quarter-finals by the Belleville Bulls.
Kingston began a rebuilding effort in the 2001-02, as many of their top players from the previous season graduated from junior hockey.
The Frontenacs took a 2–0 lead into the third period of the game, however, the Centennials responded back with six unanswered goals, defeating Kingston 6-2 and making it the first time that the club had failed to qualify for the post-season since the 1991-92 season.
The Frontenacs returned to the post-season during the 2003-04, as the club finished the season with a 30-28-7-3 record, earning 70 points and fifth place in the Eastern Conference.
Mavety named former NHL player and Kingston-native Doug Gilmour as head coach of the team.
Gilmour had been an assistant coach with the Toronto Marlies of the American Hockey League to start the 2008–09 season.
The Frontenacs were considered contenders for the 2010-11, however, Kingston struggled with injuries and slumped to a 29-30-9 record during the regular season, earning 67 points and a fifth-place finish in the Eastern Conference standings.
Following the 2010–11 season, Mavety stepped down as the Frontenacs general manager, as Doug Gilmour was named to replace him.