Yes, "Bloodsport" is loosely based on the alleged true story of Frank Dux, a martial artist who claims to have participated in and won a secret underground fighting tournament called the Kumite. The film follows his journey as he competes against various fighters from around the world. However, much of Dux's story has been met with skepticism, and many aspects of the film are dramatized for entertainment purposes. While it draws inspiration from real events, it should not be taken as an entirely factual account.

"Bloodsport" refers to a type of competition that involves physical combat where contestants engage in brutal fighting, often without the constraints of traditional rules. In the context of the 1988 film "Bloodsport," it specifically highlights the Kumite, an underground martial arts tournament where fighters from around the world compete in a no-holds-barred format. The term captures the intense, often violent nature of such events, which can include striking, grappling, and various martial arts techniques, emphasizing both skill and survival.

"Bloodsport" was rated R primarily for its intense martial arts violence and fight scenes. The film features graphic depictions of hand-to-hand combat, showcasing various fighting styles and techniques that include injuries and bloodshed. Additionally, there are instances of strong language and some mild sexual content, which contributed to its R rating. The film's focus on underground fighting tournaments and the overall tone also played a role in the rating, as it targets a more mature audience.

Frank Dux claims to have won the Kumite, a secretive martial arts tournament, which is the basis for the movie "Bloodsport." However, the legitimacy of his claims has been widely disputed. Many martial arts experts and historians argue that there is no verifiable evidence of the Kumite's existence as described by Dux, and his military and tournament records have been questioned. While the film portrays his experiences as factual, much of Dux's story remains controversial and unsubstantiated.