Knockout

Single powerful blows to the head (particularly the jawline and temple) can produce a cerebral concussion or a carotid sinus reflex with syncope and cause a sudden, dramatic KO.

In boxing and kickboxing, a knockout is usually awarded when one participant falls to the canvas and is unable to rise to their feet within a specified period of time, typically because of exhaustion, pain, disorientation, or unconsciousness.

In mixed martial arts (MMA) competitions, no time count is given after a knockdown, as the sport allows submission grappling as well as ground and pound.

[2] As many MMA fights can take place on the mat rather than standing, it is possible to score a KO via ground and pound, a common victory for grapplers.

In fighting games such as Street Fighter and Tekken, a player scores a knockout by fully depleting the opponent's health bar, with the victor being awarded the round.

[1] A double knockout, both in real-life combat sports and in fighting-based video games, occurs when both fighters trade blows and knock each other out simultaneously and are both unable to continue fighting.

There are three general manifestations of such trauma: A basic principle of boxing and other combat sports is to defend against this vulnerability by keeping both hands raised about the face and the chin tucked in.

[7] A knockdown occurs when a fighter touches the floor of the ring with any part of the body other than the feet following a hit, but is able to rise back up and continue fighting.