Stoppage time

Additional time added to the end of a soccer (football) game. Since soccer has a constantly running clock that stops for nothing, alot of "playing time" is wasted away for any these reasons: injuries, a goal scored and the celebration that follows, arguing with officials, substitutuons, red and yellow cards, and taking forever on throw-ins, free kicks, corner kicks and goal kicks. (as well as a few other posibilities) This added time ia supposed to make up for some of that wasted time. Stoppage time can be anywhere from 1 minute to 5 minutes long, but is not exact. It always just seems like the referee can stop the game randomy, and know one but him knows when the game will be final.