Capt N, what's the source of your information? I can find no reference in the FARs or on the FAA website that specifies a min. experience requirement prior to sitting the FAA ATP theory exam. I found one reference to an age limit of 21 at an ATP ground school but still no min. hours (nor can I find any FAR reference to that age limit, just FAA advice that permits parents to accompany a candidate aged less than 21 so they may provide proof of identity documents).