I thought this was a relevant off season topic. Before these NBA playoffs I would have said it was more difficult to go undefeated during an entire NFL season. Now after seeing game 4 I am not so sure. No team would have beaten the Cavs that night. It seemed even the NBA (refereeing) made sure. My answer is it depends on the competition. The Dolphins swept during a weak NFL season. That's why it would have been a greater accomplishment if Golden State swept San Antonio & the Cavs. One interesting note: The Dolphins actually had a road playoff game in their season. How does that happen to an undefeated team? The current system of BYE and home field through out may be another reason it is more difficult in the NBA. Eight of their games are on the road.