Others have, I think, answered most of Tony's questions.  Regarding scoring,
my observation is that the no-two line offside rule encouraged high scoring
games in the '70's but I think in the last 10-15 years coaches have learned
to defend all over the ice and, as a result, scoring has been reduced.  Of
course, the size and the skill of the players, plus the improvements in
equipment (especially for the goalies) may have something to do with it.

I have another question.  In the not so dark reaches of my memory, I recall
playing and watching games where there was no checking allowed in the
offensive zone.  I know the rule existed, and US high school and college
hockey was scorned upon by Canadians and the NHL because of it, but what was
the rationale behind the rule?  It seemed to give the defense an unfair
advantage once the puck was cleared into their zone.  I believe the rule was
changed in the late 60's or early 70's, true?

Greg Ambrose
GO UNH BLUE!!!