Throw in provision
 

No room on the side line so you move the defender (B1) back to give the thrower (A1) some space. After the throw in begins A1 attempts to complete the throw just inside the boundry line to A3. B1 moves back in to his original position to defend. Is this legal.

The restraining line you imposed would be 3 feet inside the boundary line and it becomes the boundary line DURING A THROW-IN ON THAT END OR SIDE OF THE COURT. Thus, B1 should not be allowed to come any closer than 3 feet to the permanent boundary line. And A1 can be anywhere behind the imposed restraining line as long as they stay on or over the designated spot, if it indeed was a designated spot throw-in.

7.6.4 situ d The b part.

Looks to me like A3 moved outside the restraining line; this is illegal and a throwin violation on A. By the time B1 moved out there, it was likely a dead ball already.

There used to be a case where A moved into the restraining area in that case B is allowed to follow. Maybe thats the case you referenced. Seems to be (or was) legal

Right. So you knew the answer to your question before you posted it? I don't get it.

For Coaches, And Fanboys, Without Casebooks ...
 

7.6.4 SITUATION D: The sideline is very near the spectators leaving little space out of bounds for A1 to make a throw-in. As a result, the administering official has directed B1 to move back a step to give the thrower some room: (a) as soon as the ball is handed or bounced to A1, B1 moves right back to the boundary line in front of A1; or (b) A1 attempts to complete the throw-in just inside the boundary line and B1 moves to his/her original position in order to defend. RULING: In (a), it is a violation by B1 and will also result in a warning for Team B which is reported to the scorer and to the head coach. Any subsequent delay-of-game situation or noncompliance with the verbal order will result in a technical foul charged to Team B. In (b), B1 is expected to stay back one step unless the throwin is attempted between this area and the boundary line. No violation in this case as B1 is allowed to defend the area if the throw-in is attempted there. (10-1-5c)

My bad, I forgot there's a difference between a marked restraining line and an "imaginary" restraining line. A marked restraining line becomes the boundary line, and A3 would violate by stepping between the restraining line and the OOB line.

The case play seamed to conflict with the rule 1 2 2 under court and equipt. I was looking for feed back to see if anyone had noticed it also. Is this a provision for if their is no actual line. if so where is that refference. Didn't mean to sound like I was setting a trap.

So if this is true can the thrower step into this area while making his throw in?

Imaginary Playing Court ???
 

I would think, yes, assuming that he's not stepping onto the playing court on the other side of the imaginary restraining line. I would also think that he could step on the imaginary restraining line.

Wasn't this covered in a recent episode of "South Park"?

Yes, the whole point is to give the thrower three feet of "breathing room."

Is It Under Rule 1-Court And Equipment ???
 

I can't find breathing room in Rule 4-Definitions. Citation please.

1-2-2. "Breathing room" is my phrase, the concept is the rule.