Sportscenter was originally started as a highlight show and at the top of its game was the best 30 min of sports on TV. It has morphed over time and shifted more to analysis than highlights. (Understandable considering the rise of immediate availability of highlights on the internet.) Here is an interesting look at the minute by minute breakdown of Sports Center.
http://deadspin.com/5878032/bristolmetrics-a-weekly-statistical-breakdown-of-sportscenter
http://deadspin.com/5878032/bristolmetrics-a-weekly-statistical-breakdown-of-sportscenter