[SoGARef]

There is often much mystery surrounding the all-but-one principle, but in fact it is really quite simple. Forget about the words "offense" and "defense". Notice SJoldguy, this is where I get my ducks back in a row! Instead, think of it this way, it is either a foul by the team in possession or the team not in possession and it occurs either behind or beyond the basic spot for that play. Two teams and two possible locations equal four categories of fouls.

If the foul is by the team "not in possession", whether behind or beyond the basic spot, or by the team "in possession beyond the basic spot", the penalty is enforced from the basic spot. This is the "all" in the name: three classifications of fouls have their penalties enforced from the basic spot. The fourth is the remaining one--by the team in possession behind the basic spot. This is the "one," and the penalty is enforced from the spot of the foul.

I'll admit it took me years to finally break it down to this simple understanding, but it hasn't failed me since.