Long before Serena Williams retired, conversations happened in the media about whether she was the greatest female tennis player of all time or the best tennis player of all time, no matter the gender. LeBron James has been called the GOAT--even ahead of Michael Jordan by some! Sports fans are always weighing stats, championships, and career length to determine who is the greatest of all time. This set presents readers with two legendary athletes and their accomplishments and asks the question: Who's the greatest? Full-color photographs complement the fun and fascinating text.