Complex sentence: It was originally awarded to the winner of the first game played in Madison Square Garden on December 15,1925 (Montreal Canadiens 3 at NY Americans 1) and then held by the Canadiens until the end of the season.
Split into simpler sentences: It was originally awarded to the winner of the first game played in Madison Square Garden, held on December 15,1925 (Montreal Canadiens 3 at New York Americans 1). The award was then held by the Canadiens until the end of the season.