<P> Clock management is a component of strategy in American football . Toward the end of either half, or of any overtime period, the time remaining on the game clock becomes increasingly relevant . </P> <P> Upon kickoff, the clock is started when a member of the receiving team touches the ball, or, if the member of the receiving team touches the ball in their end zone, carries the ball out of the end zone . The clock is stopped when that player is tackled or goes out of bounds . (The clock never starts if the receiving team downs the ball in their own end zone for a touchback .) The clock is then restarted when the offense snaps the ball for their first play and continues to run unless one of the following occurs, in which case the clock is stopped at the end of the play and restarts at the next snap unless otherwise provided: </P> <Ul> <Li> A player carrying the ball goes out of bounds . Unless after the 2 - minute warning of the first half or inside the last 5 minutes of the second half, the clock is restarted when the ball is spotted, unless another condition causes the clock to start at the snap . </Li> <Li> A loose ball is out of bounds . The clock is restarted when the ball is spotted, unless another condition causes the clock to start at the snap . </Li> <Li> A forward pass is ruled incomplete . (Included in this is the rule whereby the quarterback can "spike" the ball near himself without being called for intentional grounding .) </Li> <Li> Either team calls for a timeout or an official calls for a timeout, perhaps because a player is injured or there is a penalty on the play . Officials will restart the clock after an official timeout, but not a team timeout, has concluded unless another of the conditions applies, or if the timeout is for a penalty enforcement after the 2 - minute warning of the first half or inside the last 5 minutes of the second half (absent special timing rules for a specific foul). <Ul> <Li> 10 seconds will be taken off the clock, and the clock started when the ball is spotted, if the offense, after the 2 - minute warning of either half, fouls or commits certain other acts that cause the clock to stop (including an injury when the offense is out of timeouts, except under certain circumstances), unless the clock will stop anyway for a different reason . </Li> <Li> </Li> </Ul> </Li> <Li> A score or touchback occurs . Additionally, the clock does not run during or after a conversion attempt in the NFL or NCAA college football . </Li> <Li> Possession of the football is transferred between teams for any reason . </Li> <Li> In college football, the clock is briefly stopped when a team earns a first down to allow the chain crew to reposition themselves . The NFL has no such stoppage . </Li> <Li> The clock runs out . If this happens during a play, the current play continues until the ball is dead . </Li> </Ul>

In the nfl does the clock stop when you go out of bounds