How do you apply the rule in gym without enough room OOB so you tell the defense that they will have to stay back 3 feet from the endline until after the ball is passed inbounds? Is the inbounder now allowed to step over the OOB line without a violation? Specifically in a gym where there is only about 18 inches OOB so it is possible for A1 to stay behind the line-but impossible to throw a baseball pass without stepping onto the court?

We back up the defender but no, we do not allow the thrower to step inbounds. They'll simply have to throw something besides a baseball pass.

If you grant the 3 foot area-yes the player throwing the ball in can step over the line--but not over the "3 foot line"--I ref in many small gyms with such a problem.

Tony,
I do it pretty much the same in a couple of the Jr.High gyms and older gyms in this area.
Seems that U.P. here there's generally adequate room on the end lines, but there is more concern with the sidelines.
If I'm on my game, I'll give a pre-game, heads-up to the coaches and/or players that we may be asking the defender to give the thrower some room.
mick

If there's not enough room for the kid with the size 16's to stand there, then yea, let him go clear to the temporary inbound line. If he con comfortably stand, and shift his weight and pivot a little to find a receiver, then no, don't let him step over the real OOB line. Remember that the line is still out of bounds, so he's allowed to step on it.

On the small gyms I work at occasionaly I usually make them stand behind the line, but on the throw they can step over the line with one foot.

It doesn't really matter what rule you decide, just let both teams know in the pregame what you're going to call regarding the issue. Coaches won't really care as long as it's fair and called the same for both teams.

The thrower gets a minimum of 3' in which to step forwards/back. If there is not that much room OOB, they get use of a temporary boundary line. They get to step up to but not over the temporary boundary line until the ball is released. The defenders and teammates of the throwers are also restricted from crossing that same temporary line.

Many undersized gyms with this problem have a marked restraining line. It is no mans land for receiving inbounds passes for either team. At least that is the case with the 2 gyms in that category around here.