Here we see two clear examples of excellent swings that produce great ball control and plenty of distance without utilizing huge amounts of upper trunk movement. It is important to note the difference between a “big turn” and a coiled trunk that is stretched again by the beginning of the forward swing. Hogan was a great example of a player who overcame his size deficiency through technique, creating speed with almost perfect use of his pivot. Both Duke and Dufner have Hoganesque swings, from the general plane of the backswing to their overall rhythm and tempo (smooth but fairly fast). It is no surprise that Dufner tries to model himself after Hogan, and I wouldn’t be surprised if Duke was a big fan as well.
Another thing I like about their swings and that also mirrors Hogan is the angle at which the shaft points at the top of the swing. I would much rather see a club point left at the top as theirs do than any sort of “across the line” position.