A-1 places the ball through the boundary line during an alternating possession throw-in, and B-1 causes a held ball. Should the official award the ball to Team B?

When A-1 places the ball through the boundary line during an alternating possession throw-in, the throw-in has not yet been completed. The moment the ball is released by A-1 and comes to rest in the designated area, the throw-in counts as active, but it must be legally touched by a player on the court for the possession to be secured and the throw-in to be considered complete.

In this case, since B-1 causes a held ball before the throw-in is completed, the official should not award the ball to Team B because the throw-in situation is still in progress. The correct procedure is to recognize that the possession arrow would still indicate the alternating possession belongs to Team A, as Team B has not yet gained legal possession of the ball following the check for remaining steps of the throw-in. Therefore, Team B is not awarded the ball at this point.

It's important to understand that the throw-in must be completed for the possession to change, and in this scenario, it is not considered complete due to the definition of a valid throw-in procedure.