The term Celtic Rivals refers to the rivalry between the Los Angeles Lakers and the Boston Celtics, two of the most successful teams in the National Basketball Association (NBA). The Lakers, with six letters, are a professional basketball team based in Los Angeles, California. The Celtics, also with six letters, are a professional basketball team based in Boston, Massachusetts. The two teams have been rivals since the 1960s and have met in the NBA Finals a total of twelve times, with the Celtics winning nine of those series.