Complex sentence: Originally, panelists had to wait 20 seconds (later 30, then 45) before they could gong an act; knowing this, some contestants deliberately stopped performing just before the 45-second rule kicked in, but Barris would overrule this gambit and disqualify them.
Split into simpler sentences: Originally, panelists had to wait 20 seconds before they could gong an act; this was extended to 30 seconds and then to 45. Knowing this, some contestants deliberately stopped performing just before the 45-second rule kicked in, but Barris would overrule this gambit and disqualify them.