The phrase "to win the league" means to be crowned as the champion in a particular sports competition or tournament, specifically within a specific division or conference. This typically occurs at the end of a season when teams compete against each other for the top spot and the right to be called the best team in their respective league. To "win the league" is considered an honor and a great achievement for any team as it signifies their excellence, hard work, dedication, and skill throughout the entire season.