<<Q: Bill Parcells made a huge mistake keeping defensive coordinator Mike Zimmer. The guy can't coach with a lead. David Bair TAYLOR: I wouldn't go that far, considering Dallas had not blown a 13-point fourth-quarter lead in Parcells' 33-game tenure. The idea behind a two-deep zone is to provide deep help to the cornerbacks and prevent the opponent from getting a big pass play. The concept was sound, but the execution wasn't. Safety Roy Williams let Santana Moss get behind him twice in the final four minutes. He'll learn from this, but it's going to haunt him for a while. >> This from JJT's lastest Inside Valley Ranch.