What signifies that the ball is in play on a throw-in?

The correct indication that the ball is in play during a throw-in is when the ball touches the outside plane of the touch line. This means that the ball must completely cross the touch line and then be put back into play by the player executing the throw-in.

When a throw-in is taken, the player must ensure that the ball is thrown from behind and over their head using both hands, while both feet remain either on the ground or behind the touch line. The ball is considered in play as soon as it has crossed the outer edge of the touch line, thereby allowing the game to continue without any interruptions.

While referee signals may play a role in game management, they do not dictate the specific moment the ball is considered in play during a throw-in. The moment of contact with the ground or being caught by a player also does not indicate that the throw-in is valid, as the ball must first touch the plane of the touch line. Therefore, identifying the correct point at which the ball is in play is crucial for maintaining the flow and integrity of the game.