Throw In - Ball at disposal of a player

[Adam]

Originally Posted by Popey

We discussed this and decided it might be at different points depending on speed of game. For a slow paced walk up and down court probably would not start count until thrower with ball on out of bound side. For a fast paced 2-3 passes down the court and laying up on other end game, would probably start count as soon as B1 catches ball out of basket.
Was just checking to see if any specific rule or case book scenario we didn't know about that would give a more definitive answer to this question.

You would be wrong. The rule is the team has 5 seconds to release the throw in pass, how could you start the 5 second count before he is able to release that throw in pass?

In your OP, you grant the TO until B is legally able to execute a throw-in pass. "At the disposal" is meant to give the official leeway if B is taking more than a reasonable amount of time to get OOB and release a throw in.