[6bmike]

Just hit some balls in the backyard after my post.

What can I say Extensor Action rules.

Applying a pull to tauten the left arm from address to follow through straightens the left arm and guarantees proper delivery of the clubhead. You can have a straight left arm without applying extensor action but with none of the advantages.

If you haven't downloaded Yoda's old posts on .pdf, do so. He teaches this better than anyone.