legend  leg-end n. a nonhistorical or nonverifiable story handed down by tradition from earlier times and popularly accepted as historical.

The dictionary definition of  legend certainly does not apply to sports.

Despite the fact that performance, statistics, and records can be precisely documented, the sports world routinely recognizes legendary teams and legendary seasons. A few years will typically pass before a reference to legend is made, but sometimes a legendary season exists before it is even completed!

A legendary player will usually have a career of above average length with some significant accomplishments in the form of individual statistics or championships. Being in the Hall-of-Fame helps, but performing well over an extended period is usually enough to earn the `legendary' tag.

For coaches, there is an additional requirement -- looking old. The coach may have amassed a terrific winning record over many decades, but if he doesn't have gray hair (or very little hair) and a wrinkled, weathered face he can forget about `legendary' status. A coach can be a legend even while actively coaching -- it is not essential that he be retired.

To be a legendary announcer, broadcaster, or sportswriter the only requirements are that you have kept your job for a very long time -- in excess of three decades is a good target -- and be very old.