In 1972, Sims was the first-round draft pick of the New York Raiders of the World Hockey Association, but chose to sign with the Boston Bruins who had drafted him in the third round. At Cornwall, Ontario, inJunior Hockey he had played with Bob Murray, a rushing defenceman. When he played for Boston he was paired for two years with the greatest rushing defenceman of all time, Bobby Orr. He played for Boston and its American Hockey League affiliate for six seasons, and then for the Hartford Whalers for the next two. After his retirement from the NHL, he played and coached hockey with Fife Flyers in Scotland. Later he coached in the International League and won the Turner Cup with the Fort Wayne Komets in 1993. He was named assistant coach under Ron Wilson with the Mighty Ducks of Anaheim 1993-1996 before he became head coach of the San Jose Sharks for the 1996–97 NHL season. He then became head coach of the Milwaukee Admirals of the IHL for three years, from 1998 to 2000, moved on to the Central Hockey League for four years and to the Wilkes-Barre/Scranton Penguins as an assistant coach for a year. He is currently back in Fort Wayne, as the head coach of the Fort Wayne Komets of the IHL. In 2007-2008 he coached the Komets to his 2nd Turner Cup championship, beating the Port Huron Icehawks 4 games to 3 after a 3-OT seventh and deciding game. After that, he led them to another Turner Cup in the 2008-2009 season. And the following year, he once again led the Komets to their third straight Turner Cup. With the team returning to the CHL after the IHL dissolved, it was eliminated in the second round of the 2010-11 postseason before winning the league in 2011-12. However, the Komets failed to make the postseason in 2012-13, with the team in the ECHL, his final season as their head coach. His final minor league head coaching job came with the Evansville IceMen of the ECHL; he took over during the 2014-15 season and coached them in 2015-16, failing to make the postseason either year. The team was declared dormant in 2016-17 in preparation for moving elsewhere, which turned out to be Jacksonville, FL in 2017-18, and a new head coach took over. His son Tyler was the starting goaltender of the Providence College Friars in Hockey East, and a reserve goalie for several minor league teams between 2007–08 and 2010-11.
