Grilling 101: Put a “dimple” on your burger?

You may have your own way of grilling, but one of these suggestions you may not have know?

Now that I have a grill to cook out with.  I should use is.  Ironically, I saw this story on cooking hamburgers properly.

I didn't know you were supposed to put a dimple in your burger (basically, a thumb print) to keep the burger from cooking up like a dome.  It keeps the burger flatter.  Pre-made patties are not the right choice either.  Read the story and find out why.