A Group stage is the round robin stage of many sporting championships, particularly the World Cup of different sports. The term round-robin is used in several contexts and usually means that a number of things are taking turns at something, for example a round-robin-party where participants walk door to door for small parties at each participants habitat. ... A world cup is a global sporting competition in which the participant entities - usually National Teams or individuals representing their nation - compete for the title of world champion. ...

The name implies that there is also a knock out stage to follow. Hence a tournament that is entirely decided on a league basis would not have a group phase. A single-elimination tournament, also called a knockout or sudden death tournament, is a type of tournament where the loser of each match is immediately eliminated from winning the championship or first prize in the event. ... A list of professional sports leagues: Auto racing Champcars, formerly CART (Official Page) Formula One, Grand Prix racing (Official Site) IRL (Indy Racing League) (Official Page) NASCAR (National Association for Stock Car Auto Racing) (Official Page) NHRA (National Hot Rod Association) (Official Page) Baseball Major League Baseball Minor League Baseball...