I think it is a very important position. You have to know what you are looking at,and break it down into digestable parts for players.
Bowen played in the NBA, they have this perfected to a science.
Battier was a teammate, and he took it to a new level in application of info of all tendancies of guys he guarded like Kobe on to the hardwood.
I remember reading about how he knew exactly where he wanted to push kobe on the floor and where kobe wanted to push him,and he anticipated very well...everyone has spots they shoot well from..and he would not allow those shots.
Here is a link to the article about Battier. It is very long but worth the time if you have an interest in the level of detail that goes into game-planning on the highest level of basketball.
http://www.nytimes.com/2009/02/15/magazine/15Battier-t.html