A group stage (also known as pool play or the pool stage) is the round robin stage of many sporting championships, particularly a sports' world cup. The name implies that there is also a knock out stage to follow. For example in both the FIFA World Cup and Rugby World Cup the teams are split into groups (also known as pools) where they play each team in their group once under a round robin system. Points are earned during group play in order to rank the teams within a group. The top ranked teams (often the top two) from each group then proceed to the tournament's knock out phase. From there the tournament continues under a knock out system until the winner is found.
