Clock management is most prominently used as a strategy in American football, where an elaborate set of rules dictates when the game clock stops between downs, and when it continues to run. Clock management strategies are also seen in basketball.
In gridiron football
Rules for the game clock
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:
- 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/overtime, the clock is restarted when the ball is spotted, unless another condition causes the clock to start at the snap.
- 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.
- A forward pass is ruled incomplete.
- 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/overtime (absent special timing rules for specific fouls).
- 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. In Canadian football, the offense may execute one additional untimed play if the clock expires while the ball is not in play.
- A score or touchback occurs. Additionally, the clock does not run during or after a conversion attempt in the NFL or NCAA college football.
- Possession of the football is transferred between teams for any reason.
- 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.
If the clock runs out during a play, the current play is allowed to continue to its conclusion. If the clock runs out between downs, the period ends in American football, but in Canadian football the offense is allowed one last down.
Each team is given three timeouts per half which they can use to stop the clock from running after a play. In the NFL, teams get two timeouts in a preseason or regular season overtime period, or three in a postseason overtime half.
On a fair-catch punt, the clock starts at the snap and stops at the end of the play.
A team on offense that has the higher score seeks to use as much time as possible. A drive that scores no points may nevertheless benefit the team by taking time off the clock. The team may:
- Favor run plays over pass plays.
- Use the center of the field rather than the sidelines to avoid going out of bounds and stopping the clock.
- Delay the start of each play until the play clock approaches 0.
The team may use counterintuitive game plans, such as declining to score or allowing the opponents to score, to accelerate the end of the game.
If the defense does not have enough time-outs to stop the clock before the ball is turned over on downs, the offense can run out the clock by executing repeated quarterback kneels until the clock runs out. In the NFL and college football, up to 40 seconds can be taken off the clock between plays. The NFL also has a built-in two-minute warning that stops the clock after the play that occurs when the clock hits two minutes ends. In order to successfully run out the clock by kneeling, there must be less than 40 seconds on the clock if the opponent has two time-outs, 1 minute 20 seconds if the opponent has one time-out, or 2 minutes if the defense has no time-outs remaining, at the beginning of the series of downs. The offense can burn further time off the clock by timewasting: keeping the ball live (and the clock running) simply by keeping away from any defensive player, regardless of position on the field.
A team on offense that has the lower score seeks to conserve time. The team may:
- Use a no-huddle offense; forgo detailed design of a play and instead signal and initiate a play quickly.
- Have the quarterback "spike" the ball, sacrificing a down to stop the clock. (An explicit exception is written into the American football rule books so that the move is not penalized for intentional grounding.)
- Use a passing play (because an incomplete pass stops the clock) or a run play toward the sidelines (because taking the ball out of bounds also stops the clock).
- Most ideal after a 1st down.
- If a play ends such that the game clock continues running, use a timeout.
- If the ball is still alive while the clock runs out and the team with the ball is still trailing, do everything within the team's power to keep the ball alive until it can be advanced to the end zone. Often this incorporates a series of lateral and backward passes to avoid the ball carrier being tackled and the game ending.
A team that is tied or trailing by one or two points but is within the red zone (and thus in easy field goal range) seeks to burn a specific amount of time off the clock, such that they can stop the clock with five or fewer seconds on the clock, so that their placekicker can kick a field goal with no time remaining and win the game.
A team on defense has little control over the pace of the game. It may expend its timeouts to ensure that there is adequate time left on the clock, in case the team regains possession. The defense can make decisions on how to stop the ball carrier based on whether the team is trailing or leading: if the offense is trying to conserve time, the defense can foil that by tackling the ball carrier in-bounds before they can get out of bounds. Defenses likewise can safely devote more personnel to the perimeter and leave the center of the field less defended, as an offense that cannot afford to keep the clock running will have to throw toward the sidelines. Various rules ensure that the defense cannot deliberately commit fouls to manipulate the game clock, and in the most extreme such cases, an unfair act can be declared and the game forfeited to the offense. (Likewise, if the offense commits fouls to burn off time and get extra downs, the clock is reset and unsportsmanlike conduct is called on them.)
In Canadian football, a team trailing by one point or tied has an additional option: a ball can be kicked from anywhere on the field in that sport, and balls kicked into or through the end zone and not returned score a single point. This allows a team trailing by one to advance the ball upfield, then punt the ball toward the end zone in hopes of tying the game for one point (the player could also drop kick the ball, which would allow the kicking team to win on a field goal if kicked through the uprights). To prevent this scenario, defending teams will place their punter in the end zone to retrieve the ball and kick it back out of the end zone, preventing that single point from being scored.
Clock management is also a component of the game of basketball. In that sport, the rules governing the game clock are simpler; the clock stops when the ball is dead and runs when it is live. Most clock management in basketball centers around both the game clock and the shot clock. An offense nearing the end of a game and holding a slim lead will attempt to use up as much of both clocks as possible before shooting the ball to give the opposing team as little time as possible to respond.
Defenses, in contrast to football where there are stiff penalties against the practice, routinely commit intentional personal fouls by making contact with the person in possession of the ball, immediately forcing them to take free throws and stopping the game clock (when the player being fouled is a known poor free throw shooter, this strategy is known as hack-a-Shaq); once the free throws are taken, the fouling team then gets possession of the ball. The defensive team thus gets the ball back sooner by committing the foul than they would by playing clean and allowing the offense to run out the clock.
- "2016 NFL Rulebook". NFL Football Operations. Rule 4, Sections 3 & 4. Retrieved 2017-03-17.