When ruling on an illegal screen, it is important to identify if the screen is legal and to consider the effect of the screen on the play.
There are several things going on in the following video, one concerning the rules for an illegal screen and another concerning the floor mechanics. We will look at the rules for screens first.
The Rule on Screens
Rule 4-40 states, in part, “A screen is legal action by a player who, without causing contact, delays or prevents an opponent from reaching a desired position,” and continues “to establish a legal screen position… c. the screener must be stationary… d. The screener must stay within his/her vertical plane with a stance approximately shoulder width apart.”
In this play, White #44 and White #1 both set screens to free up the shooter. It is easy to rule the screen set by #1 as legal because there was no contact on the defender, however, the cross screen set by White #44 is an illegal screen. This is harder to pick up as the player is moving towards the center official who is straight-lined.
This is where the mechanics discussion comes in on this play. The legality of this screen is determined by the center official. It is important for the center official’s eyes to stay with the defender who is trying to maneuver through these multiple screens. By staying with the defender, it is easy to see her get bumped out by the white #44. However, on this play, it seems the center official follows the offensive player out to the top of the key, taking his attention away from the screening action.
The end result, the defender is late getting to the shooter and commits an airborne shooter foul by not allowing her to come back down. This is why it is important to consider the effect of a screen on the play.