How many times did Sugar Ray Robinson win a boxing world championship?

Sugar Ray Robinson (born Walker Smith Jr.; May 3, 1921 – April 12, 1989) was an American professional boxer who competed from 1940 to 1965. Widely considered the greatest pound-for-pound boxer of all time, Robinson's performances in the welterweight and middleweight divisions prompted sportswriters to create "pound for pound" rankings, where they compared fighters regardless of weight. He was inducted into the International Boxing Hall of Fame in 1990.

In total Robinson won six boxing championships. He first held the world welterweight title from 1946 to 1951, and won the world middleweight title in the latter year. He retired in 1952, only to come back two and a half years later and regain the middleweight title in 1955. He then went on to become the first boxer in history to win a divisional world championship five times (a feat he accomplished by defeating Carmen Basilio in 1958 to regain the middleweight championship). Robinson was named "fighter of the year" twice: first for his performances in 1942, then nine years and over 90 fights later, for his efforts in 1951.