Nicknamed "Jumpin' Jackie", Forbes was involved in the infamous 1925 Hamilton Tigers players' strike. Before becoming involved in the players strike, Forbes played for the Toronto St. Patricks and sat out the entire 1921–22 NHL season while holding out for a $2500 salary. In doing so, Forbes became the first NHL player to sit out an entire season due to a contract dispute. His contract was then sold to Hamilton after the season ended. He spent most of his career with the perpetually benighted Hamilton Tigers-New York Americans franchise. After getting into two playoff games in 1921, his first full season, he never played another post-season game despite not retiring from the league for another twelve years. His only other opportunity at winning a Stanley Cup was foiled by the Hamilton players strike. In his NHL career, he finished with 84 wins, 114 losses and 11 ties, with a 2.76 goals-against average.