The conflict between the NFL hiearchy and the individual teams can be summed up thus: 1. The NFL wants to appease it's teams in their desire to get calls RIGHT without embarrassing NFL officials or making them look bad in the publics' eyes. In addition, they don't want to lengthen games significantly, a legitimite concern.2. Teams, OTOH, generally just want to get official's calls made correctly. Here is my approach: Any team can challenge any call EXCEPT the dreaded "inadvertant whistle". To avoid lengthening games, THE CATCH is each team has a limit of 2 INCORRECT challenges, each of which also cost them a timeout. After that, they can no longer issue a challenge. If a team CORRECTLY challenges a call, they are not charged a timeout, and may challenge any later play.