Open Division is a Blizzard-run league, that was originally open to all players who placed in Masters or higher in the most recent season of ranked Competitive Play.
Beginning in 2018, Open Division became integrated into Overwatch Contenders in the Path to Pro. There is no longer an SR requirement to joining Open Division. The top teams from a season of Open Division would now get to play the bottom teams from the previous season of Contenders, in a relegation tournament named Trials. The top teams in Trials would go on to play in the following Contenders season.