The double-top-secret difference between a "Good" coach and an "Elite" coach is simply a better, healthier roster. Even Pop without a healthy TD, TP, and/or Gino is merely a GOOD coach (see: 2000, 2009, 2011). With healthy stars, Pop is ELITE (see: 1999, '03, '05, '07).
Rivers seems to connect with his players, has a system that EVERYONE buys into, and thus gets the most from his roster. Unfortunately, Rivers has been hamstrung year after year by the same parade of injuries and age-related longer recovery periods that the Spurs have been dealing with for the last 5 years.
to see the rest of my "oversized" signature. "Leadership is diving after loose balls." -Larry Bird