They stop the clock anytime the play stops. Television has more control over the length of the game than the players, coaches or referees. When the play is interrupted it cannot start without permission of the TV man who from the sidelines signal the referee when it is time to resume the game. Television tells the referee when it should stop the game in order to broadcast its commercials. The climax of this game is the final match which they call Super Bowl, and whoever wins it is known as the football champions of the world.
Baseball is even stranger.
The players also wear drawers, but unlike their football counterparts, they don't wear any protective gear, except for the player who catches the ball. All wear big gloves in one hand. The position players have funny names. The referees are called umpires and don't use whistles. They call the plays by mouth, yelling, and some make funny screaming noises with harsh high tones and hysterical expressions.