Found the play in Reddings today. (Ch. 11-48.)

Explanation for why it's a safety is once the pass is intercepted, the succeeding spot - B's 20 - becomes the basic spot. Yes, while the play continues.

Because the foul occurs behind the basic spot, All but One, and in the end zone, result is a safety.

I agree with a rule change as A is rewarded two points for throwing an interception.

Thanks for the help.

Well, we told you that above. :D

And I think it's a perfectly fine application of the rules. Holding in the end zone has consequences.

I'm much more annoyed about using all-but-one on offensive penalties behind the line of scrimmage -- 10 yards from the previous spot is more than enough for a holding penalty, for example. And I'd love to be able to apply K fouls at the end of kicks like in NCAA football.

This is all about what you think might've happened in the absence of the foul. The pros were 1st to change this, about 40 yrs. ago, in the assumption that if team A hadn't committed illegal use of hands, there would've been an incomplete pass rather than a sacking.

However, if a foul by A springs the runner for a gain, why should it matter whether that gain was from a point behind or beyond the previous spot?

Have I mentioned how much I love that all of my games are played under NCAA rules?

The point is, the A player was held and never had the opportunity to tackle the B player and cause the fumble. Then there is no penalty to decline. That's the What If? scenario.