There are two types of throw-ins. Designated and non-designated
Designated throw-ins require the official to indicate the ‘throw-in spot” and put the ball at the disposal of the thrower.
The designated throw-in spot is 3 feet wide and extends in depth as far as the playing venue will let it.
It extends in height to the ceiling.
The thrower must keep one foot on or over the throw-in spot until the ball is released.
If the thrower leaves the 3-foot throw-in spot before releasing the ball the thrower has violated the throw-in provisions.
All sideline throw-ins are designated.
End line throw-ins may be designated or non-designated.
The official must always handle the ball and put it at the disposal of the thrower for all designated throw-ins
On most all non-designated throw-ins the officials will not need to handle the ball.
Exceptions include timeouts following a made field goal or free throw.
The ball becomes “live” and the 5-second throw-in count begins on a throw-in when the ball is at the disposal of the thrower.
That means when the official has bounced or handed the ball to the thrower and she has caught or possessed, it the ball becomes “live.”
The ball is also at the disposal of the thrower when it is on the floor and available to the thrower after a made basket or free throw.
The ball is also at the disposal of the thrower when the official puts the ball on the floor when utilizing the “resumption of play” procedure.
The ball is “live” and there is team control during a throw-in.
Recall that the ball becomes dead following a made free throw or made field goal and remains dead until it is at the disposal of the thrower.
All dead ball contact is “Technical” and all live ball contact is “personal.”
Throw-in violations include:
Leaving the designated throw-in spot before releasing the ball for the throw-in (This happens on occasion)
Failure to release the ball for the throw-in within 5-seconds (Probably the most common violation)
Carrying the ball onto the court. (Happen occasionally)
The thrower touching the ball on the court before it is touched by another player. (I have had this once or twice)
Having the thrown ball go out of bounds without being touched by a player on the floor. (This can happen)
The thrown ball shall not be touched by a teammate of the thrower while it is on the out of bounds side of the boundary line. (Probably will never happen or if it does you will likely space it)
Lodging the ball between the ring and the backboard, (Rare, but has happened.)
Throwing the ball into the basket (Very rare, but I have seen it)
No teammate of the thrower may be out of bounds after the designated throw-in starts. (Possible, but not probable)
Recall that the penalty for a throw-in violation is basically a turnover and the opponents will throw the ball in from the spot of the original throw-in.
Remember that the non-scoring team always retains the privilege of running the end line after a made basket or free throw.
They retain that privilege even if the throwing team commits a common foul or violation where an ensuing throw-in would be from the end line.
The throwing team retains the privilege of running the end line even if there is a substitution following a made free throw.
Also, if the scoring team is granted a timeout the throwing team still retains the privilege of running the baseline after the timeout ends.