indicative of the skill/quality of the scrum. For example, once the ball has been hooked and brought to the back of the scrum, the 8 man can keep it in front of his feet as the scrum half surveys his options. Sometimes the dominant scrum might keep the ball under feet and push forward (for a variety of reasons). The scrum, by design, ties up all 8 defending forwards; so if the team winning the scrum wants to play expansive rugby they will spin it out wide quickly.
BYU generally recycled fast off the scrums and rucks when possible because our loose forwards and inside backs (fly half, centers) are some of our top athletes and we had mismatches all day against Cal in these areas. We were able to suck in multiple defenders, opening gaps and providing great kicking opportunities.