What is the fine-grained topic of the following text: As collectibles and sports memorabilia go, Joe Frazier’s jock strap is definitely a rare item, but this is made all the more valuable by the fact that this legendary boxer who won this equally legendary fight is still a household name in a sport that doesn’t have as many of those as other popular spots in the United States. Only return the topic.
Joe Frazier's jock strap as a valuable piece of sports memorabilia