Yer right on that one..and it's Theisman. I only know cuz I eat at his restaurant :)
Gibb's great secret wasn't that he whupped up on the good teams..which the Cowboys were. His secret was that he almost never lost to a bad or mediocre team and played .500 with the good teams. That always got him into the playoffs.
Once he got into the playoffs his coaching ability and a little bit of good fortune carried him to the SB.
But it used to be Thiesman. He changed it in college in order to make his name sound more like the Heisman trophy. (at his dad's suggestion after they mispelled his name in a report somewhere)