The game clock has a mind of its own...

When does the NFL game clock stop? Some reasons...

• A timeout is called (duh, right?)
• The person with the ball runs out of bounds (this is important when there's not much time left in the half)
• There's an injured player on the field (although sometimes the team has to use a timeout then too - it depends)
• The red challenge flag is thrown by a coach (which means the referees review the previous play to see if the decision needs to be changed)
• It is the 2-minute warning (this is at the end of the 2nd and 4th quarters)
• Change of possession (interception, score, punt, etc.)

Sometimes you won't realize the clock stopped because they'll switch to a TV commercial.