10 secound backcourt or not

[Adam]

Originally Posted by Nevadaref

You might want to check when is the proper time to start the shot clock.

Okay, allow me to ask, then.
Play:
BC throwin for A with new shot clock. Throwin is tipped by a) A2, who does not gain control or b) B1, who does not gain control, before being controlled by A3 (two seconds later for the sake of clarity).

When do you start the shot clock?