NFHS
It would be a technical foul per 10-4-5a.

Seriously? Does this mean that as soon as the ball goes through the hoop that you start counting? Where the ball and inbounder are located absolutely are relevant here.

This is true AFTER the IB officially begins. But if a player has the ball and is on his way OB to begin the throw in and it is knocked out of his hands? I'd like to think we would all have a T there. I believe that what you are referring to is the situation where the inbounder reaches the ball through the plane, and that is touched/dislodged by the defender.

Yes, seriously. No, not as soon as it goes through the hoop because when the ball goes through the hoop, it is not readily available. Throw-in starts and count starts when ball is at the disposal of the thrower. I do not feel that ball and inbounder location are relevant to when throwin/count start as it is not described in the throw-in administration. An an example, the ball goes through the hoop, bounces, and comes to rest IB. The thrower, also IB, stands next to the ball for 3 seconds. Clearly, the ball is at his disposal and a count would be started. neither ball, nor thrower were OB but rather IB. The ball's location and the thrower's location, as far as IB/OB, matter not.

No. Slapping the ball out of his hands is an unsporting act and is an automatic T.

Fair enough, but if the eventual inbounder is clearly on their way to securing the ball and is going straight OOB, then you will hold the start of your count until they are there correct? That is why I don't think you can say that the location of either has "nothing" to do with the start of the throw in.

When does it start, then? What is disposal? What criteria are used to start the count?

Seems to me that "Not Really An Official" needs to spend a little more time reading and understanding the concepts of this game and the input given by "Really an Official".

To answer your question, generally speaking, yes. The location indeed has nothing to do with the start of the throw-in in terms of the definition.

You mentioned going straight OOB, which to me implies some sort of speed/urgency. In that case, yes, waiting a bit seems appropriate. Now, imagine the thrower obtaining the ball at the top of the key (ball got inadvertently knocked there after a basket). He turns, and walks very, very slowly towards the endline, looking at his coach/others for some sort of direction or looking for perhaps someone else who is supposed to take the ball OOB. Looks like a stall tactic or confusion on their part. In that case, I am not waiting until he gets OOB before starting my count. Again, generally speaking, yes, wait until they have secured the ball and get OOB.

99 times out of 100, you should not start the count until the thrower has the ball OOB and is looking for a teammate. This is what Camron was getting at. The fact that there are exceptions does not change that fact.

(moderator note) I'm not going to address your other garbage, Camron seems to have done that well enough, other than to say it really needs to stop now.

Citation ...
 

A player shall not: Delay the game by acts such as:
a. Preventing the ball from being made live promptly or from being put in
play.
b. Failing when in possession, to immediately pass the ball to the nearer
official when a whistle blows.
c. The free thrower fails to be in the free-throw semicircle when the official is
ready to administer the free throw unless the resumption-of-play procedure
is in effect following a time-out or intermission.
d. Repeated violations of the throw-in, as in 9-2-10.

I understand that slapping the ball out of the hands of an inbounder who is out of bounds is an immediate technical foul, but in this case the "inbounder" is still inbounds (the throwin hasn't started). Isn't that interfering with the ball following a goal, and thus deserving of a delay warning (or technical foul for the second delay)?

10.3.10 SITUATION A: After a field goal, A1 has the ball out of bounds for a
throw-in. Thrower A1 holds the ball: (a) B2 crosses the boundary line and fouls
A1; or (b) B2 reaches through the out-of-bounds plane and touches the ball while
in the hands of A1. RULING: It is an intentional personal foul in (a), and a technical
foul in (b). In (a), such a contact foul with the thrower during a throw-in
shall be considered intentional, or if it is violent, it should be ruled flagrant.
COMMENT: Either act is a foul and it should be called whenever it occurs during
a game without regard to time or score or whether the team had or had not been
warned for a delay-of-game situation. If the player making the throw-in (A1)
reaches through the out-of-bounds plane into the court and B1 then slaps the ball
from the hand of A1, no violation has occurred. B1 has merely slapped a live ball
from the hands of A1. (4-19-3, 4; 9-2-10 Penalty 3, 4)

10.3.10 SITUATION D: A1 is out of bounds for a throw-in. B1 reaches through
the boundary plane and knocks the ball out of A1’s hands. Earlier in the game,
Team B had received a team warning for delay. RULING: Even though Team B had
already been issued a warning for team delay, when B1breaks the plane and subsequently
contacts the ball in the thrower’s hand, it is considered all the same act
and the end result is penalized. A player technical foul is assessed to B1; two free
throws and a division line throw-in for Team A will follow. The previous warning
for team delay still applies with any subsequent team delay resulting in a team
technical foul. (4-47; 9-2-10 Penalty 3; 10-1-5c)

So if a player who has two hands on the ball is on their way out of bounds to in bound the ball, and a defender slaps it out of their hands, you're not going to call the T, and instead call it a delay of game warning? I think that is allowing the defender to get away with what I would call a clear and obvious unsporting act. No reason to swat at what is clearly a dead ball at any point for any reason. In fact, allowing him to get away with that only increases the chances that someone on the other team might react in a negative way. Punish the instigator before it escalates.

Confused In Connecticut ...
 

That's what I'm asking. If instead of slapping the ball out of the player's hands, the defensive player simply slaps the ball away before the offensive player can get his hands on the ball, aren't we calling a delay here?

Yes, but you've changed the play to something completely different.

Yes, that is a delay. I had interpreted your original statement as slapping the ball away from an inbounder who had possession of it, but just had not ran out of bounds to begin the throw-in yet.

It could be either a delay or a T depending on how you judge the action. Do they delay it or prevent it? Do they just knock the ball out of reach or do they bat/throw it into the stands? (10-4-5a)