1
Granted, I've only watched about 50 soccer games from Europe, which is about 1% of what some of these guys have.
But in those 50 games I've never heard an announcer refer to offside in the way that you just excerpted from the rule book -- not a single time. Just like I've never heard Dave Niehaus chew out an umpire by quoting a rule-book strike zone on him...
They draw the little shadow line based on where the #2 defender's back foot is, and then analyze whether the attacker's body is mostly over, or mostly behind, that line ... and then chew the ref out for calling it where doubt exists.
Perhaps CPB or GL can help us out here ...