That was my recollection as well (going back to 1965), but since I never thought specifically about it I didn't think that my opinion was worth much. That video of Staubach to Pearson that @ukjetsfan found is reassuring to me that that impression was correct.
I also found a really old rule book from 1915. It was so old it was written by Walter Camp and was called "Foot Ball Rules". It had no mention of any sort of forceout rule... so it was introduced somewhere in the 60 years between 1915 and 1975!
I'm like a dog with a bone with this sort of thing... I'm a historian and I love research.. I don't often get to research around the NFL so this is actually fun for me!
break out the microfiche! i feel as though it has been around as long as i have watched football. it was one of those rules that was different in the pros vs college. in college you could force a guy out in the nfl you couldnt. glad it got changed.
I would suggest that may have been in the 1940's when significant changes in the rules were made to accommodate the recognition that passing had become a major part of the game.
I’m glad the rule was done because I remember that Chris Baker screw job play by the refs so if they weren’t going to call it for us then they might as well get rid of it. Also I’m glad a rule went the defenses way for once. There’s a bit too much offense in this game and wish they dialed it back a bit.