OK then...how about we say that you can't score a 3 at your opponents basket?

Sure. But the OP was toward and into A's basket.

It was a throw-in. Ended when touched by defender. Can't score 3 in opponents basket.

"If the original release had no chance at being worth three points, then the deflection can't be worth three points."

(edit: NCAA interp only. FED might be different.)

I think I see where you're going. But it's still a pass by A that goes into A's basket. It's not B scoring at A's basket.

I like it.

I can't find a case on this, but I remember my association's interpreter giving a similar example when I went through training a couple years ago.

A1, outside the three point line attempts to throw the ball into the post. B1, also outside the 3 point line, deflects the pass and it goes into the basket. I'm 99% sure the instruction was "3 points" [FED rules]

Does the fact that the original pass was a throw in change the ruling?

Yes.

The only way I would count 3 here is if the original pass was at such an angle as I couldn't tell if it had a chance to go in. If he's throwing a lob pass, then I'd be inclined to count it as three. If he's throwing a bounce pass and the initial trajectory is down (or even horizontal), I'd count it as 2.

On a throw in, I'd go 2 regardless.

Consider this play:

A1, in his backcourt, throws a pass towards A2, who is crossing into the FC. The pass is hits a) A2 or b) B2 (either is running outside the arc) in the head and caroms into the basket.

2 or 3?

The NFHS rule is different than the NCAA rule. Any "thrown ball from the field" beyond the 3-point arc that enters the basket is 3 points under NFHS rule. One need not judge if this is a pass or not. NCAA requires the official to judge whether it is a pass or a try.

And yes (in my reading of the rule)...it does matter if it is a throw-in. The rule says score 3 points on a ball "from the field" beyond the arc. Being out-of-bounds does not place you on the "field."

3 points (NFHS). Case book 5.2.1 Situation C.

The ball was thrown from outside the arc; it was legally touched outside the arc; it entered the basket. All the elements of this counting as 3 points are met.

Wrong, it seems, because the OP deals with a throw - in .
How ridiculous would it be if the ball was administered for the throw in between the lane line and the 3 point arc... would a person then assess at as being thrown from inside the arc (from OOB) therefore the defected ball would then be only 2 points? That doesn't make sense because it was not thrown "from the field". Right?

That's just it...it is NOT a pass. That pass officially ended. It's also not a try. So can't be 3 points.

This is where I would invoke 5.2.1 Situation D.

"Following the free throws for a technical foul, A1 makes a throw-in from out of bounds at the division line opposite the table. The throw-in pass is deflected at A’s free-throw line by: (a) A2; or (b) B1 and it then goes directly through A’s basket.

RULING: Score two points for Team A in both (a) and (b). The throw-in ended when the ball was touched by an inbounds player (legal touch) and the live ball subsequently passed through the basket. The fact it was not a tap or a try for goal does not affect the scoring of two points. (4-41-4; 5-2-1)"

If you will notice in 5.2.1 Situation C, the play also references a "legal touch". 5-2-1 is irrelevant to this situation as it only deals with the qualifications for a legal try or tap. This situation is a deflection.

Simply being deflected by B does not change the status of this thrown ball, which still meets the definition of a pass. The throw-in, by definition and rule, has ended on the B legal touch, but it's still a pass.