NBA RULE AUTHORITY

Welcome to our second installment of the NBA Rule Authority in the 2012-13 season. We will continue to post explanations to this page to some of the NBA’s more complicated rules throughout the season. This week’s topic is trajectory of defenders in the Restricted Area (RA).
We get a lot of questions about block charge plays and the RA (see block-charge explanation posted January 23, 2012). In this installment, we’ll discuss when defenders may be in the RA and what they can do if they’re in it, much of which hinges on the defender’s “verticality.”
First, if a driving offensive player received the ball inside the lower defensive box, which is the area from the bottom tip of the free throw circle to the endline between the two 3′ posted-up marks, a secondary defender can be in the RA and draw an offensive foul if (i) he established a legal guarding position before the offensive player’s upward shooting motion, and (ii) the contact is more than marginal.
However, if the offensive player received the ball outside the lower defensive box , the secondary defensive can only draw an offensive foul inside the RA if (i) he is in a legal guarding position before the offensive player’s upward shooting motion, (ii) he jumps vertically in an attempt to defend the shot, and (iii) the contact is more than marginal. If all of these factors are met, the contact is an offensive foul, otherwise, it is a defensive foul (unless the offensive player did something unnatural and/or dangerous).
Below are two examples that will help you better understand what it is referees are looking for on these types of plays.
Play 1: Legal Defensive play, defender jumps vertically:
http://www.nba.com/video/channels/originals/2013/01/16/defensive-foul.nba/index.html
Play 2: Defensive Foul, Not Verticality, defender jumps toward offensive player:
http://www.nba.com/video/channels/originals/2013/01/16/legal-defensive-play.nba/index.html
Check back for additional installments and other topics or sign up for twitter alerts @NBAOfficial, and be sure to check out nba.com/videorulebook for a variety of explanatory rule videos.