knockouts

Knockouts, in plural, is a term used in various contexts to denote a decisive end to an activity. In combat sports, a knockout (KO) occurs when a fighter is rendered unable to continue due to a legal strike, typically defined by loss of consciousness or inability to regain footing within a referee's count. A related outcome, a technical knockout (TKO), occurs when the referee stops the contest because a competitor cannot safely continue. The methods and criteria vary by sport and jurisdiction, but the core idea is an immediate or decisive end to the fight.

In genetics and biology, a gene knockout refers to the deliberate inactivation or removal of a gene to study its function. Knockouts are created using techniques such as homologous recombination in organisms or gene editing tools like CRISPR-Cas9. Knockout models, especially knockout mice, are widely used to investigate disease mechanisms, gene roles, and drug targets. Limitations include genetic redundancy and compensatory pathways, which can obscure effects, and ethical/regulatory considerations for animal research.

In competition formats, a knockout tournament, also called single-elimination, advances participants by eliminating those who lose a match. Brackets, seeding, and byes structure the event, with the overall champion determined by successive rounds until one competitor remains. The format is efficient for determining a clear winner but can produce early exits for strong competitors and may not reflect overall consistency across multiple matches.