A clock-killing neg is a strategy employed during tournaments that use a clock. While leading by more than 5, but less than the maximum possible points in a tossup-bonus cycle, a team may choose to buzz in with few seconds remaining, use the maximum amount of allotted time to begin a response, and then deliver as long an answer as possible, thus ensuring that the clock runs out before the trailing team can buzz. If a tossup-bonus cycle concludes with only a few seconds left, the team ahead may immediately buzz and just wait for time to run out.
Clock-killing negs are risky, since a player/coach in charge of keeping score may have added wrong and a team may actually lose the game by 5 points instead of win by 5 points. In addition, some moderators will cut a team off once it becomes apparent that the team is attempting a clock-killing neg, allowing the trailing team a guess before time runs out.
A variant of the clock-killing neg is used in formats with bounceback bonuses. If a team is up by less than (maximum possible bonus points - maximum possible tossup points), and the other team has already missed the question, the team that is ahead may buzz in and intentionally miss the question to prevent the possibility of losing on bonus bounceback points. In formats where the tossup goes dead once any team misses it, a team clinging to a slight lead with only one question remaining may also buzz in and say a wrong answer (or nothing) in order to preserve the victory.