3 man mechanic on sideline throw in below free throw line extended!!!!

[jritchie]

in nfhs the trail comes all the way to the baseline for the throw in.
But in NCAA, the Lead is supposed to come out and take it...

i've heard several conversations on who supposed to have the count and who supposed to chop time in!

my question who "Actually supposed to have it"???

i'm thinking that if the lead is administering the throw, they should have the count and chop in time, but if that is happening, who is watching the post play??? Trail?? just want to be clear on how this mechanic is supposed to be done, and who has what responsibilities!!! Does primarys change till ball comes in??? thanks