When do you start the count

[justacoach]

Originally Posted by bob jenkins

There's a specific case play or interp on this -- and I agree with 2.

9.8 SITUATION D:Team A is in control in its backcourt for seven seconds. A1
throws the ball toward A2 in the frontcourt. B1 jumps from Team A’s: (a) frontcourt; or (b) backcourt and while in the air bats the ball back to A1 in A’s backcourt. Does this give Team A 10 more seconds to get the ball to the frontcourt?
RULING: Yes, in (a), a new count starts because B1 had frontcourt location when
touching the ball thus giving the ball frontcourt location. In (b), the original count
continues as Team A is still in control and the ball has not gone to frontcourt. (4-4-2; 4-3; 4-35-1)

thus, according to 9-8-1...
SECTION 8 TEN SECONDS
A player shall not be, nor may his/her team be, in continuous control of a ball
which is in his/her backcourt for 10 seconds.
PENALTY: The ball is dead when the violation occurs and is awarded to the
opponents for a throw-in from the designated out-of-bounds spot nearest the
violation.

The 10 second count starts when the ball attains backcourt status, regardless of where the ball originated. To do otherwise disadvantages the defense, who have successfully defended their frontcourt from penetration by the offense.
QED