Terminology
The term round-robin is derived from the term ruban, meaning "ribbon". Over a long period of time, the term was corrupted and idiomized to robin.
In a single round-robin schedule, each participant plays every other participant once. If each participant plays all others twice, this is frequently called a double round-robin. The term is rarely used when all participants play one another more than twice, and is never used when one participant plays others an unequal number of times (as is the case in almost all of the major United States professional sports leagues - see AFL (1940-41) and All-America Football Conference for exceptions).
In the United Kingdom, a round-robin tournament is often called an American tournament in sports such as tennis or billiards which usually have knockout tournaments. In Italian it is called girone all'italiana (literally "Italian-style circuit"). In Serbian it is called the Berger system (Бергеров систем, Bergerov sistem), after chess player Johann Berger. A round-robin tournament with four players is sometimes called a "quad".
Read more about this topic: Round-robin Tournament