Knockout is a 1977 NBC game show hosted by Arte Johnson and aired as a replacement for It's Anybody's Guess. Based on the British show Odd One Out, players were given a list of four items, with one of them having no relation to the other three. The first person to buzz in would try to guess the unrelated item, and if he/she got the right answer, a letter in the word "KNOCKOUT" would light up. Said player would then find an opportunity to earn more letters by either guessing the category that the three related items are in or daring someone else to answer. If the dare was successful or the category was correctly guessed, the contestant won two letters, and if the opponent got it right, they got two letters. The first person to light up the entire "KNOCKOUT" word would win the game.
Typical for game shows of the era, the series was wiped after its cancellation. However, three episodes survive, and the premiere exists via audio tape.