Question about perimeter weighting in golf clubs

[Duster22]

From How Stuff Works:

"In the last 25 years, designers have developed clubs that have approximately the same weight as the older clubs but have it distributed around the perimeter of the club, so that the head is far more resistant to off-center twisting and therefore far more forgiving of golf swings that are off line by a few millimeters."
<http://entertainment.howstuffworks.com/sports/golf/basics/golf-club2.htm>

How does perimeter weighting cause the club head to twist less when shots are hit off centre?
I am also having trouble picturing what axis the head would be twisting around: if it rotates about the shaft then wouldn't the collision producing the least twisting occur right at the shaft (the heel of the clubhead)?

Thanks

 

[LightHero]

!Perimeter weighting causes the club head to twist less when shots are hit off-center because it distributes the weight of the club around the perimeter of the head. This creates a more balanced structure that is less likely to twist when an off-center shot is hit. The axis that the head would be twisting around is the center of the shaft. The heel of the clubhead would be the furthest point from the center of the shaft, and therefore the most vulnerable to twisting.