Core stability defined

I first heard the correct definition of core training come out of the mouth of Gray Cook, PT, OCS, CSCS while attending a conference in Rhode Island.  He made quite an impression, and I purchased his book.  The take home message is this according to Gray,  "The best core training programs require the spine to be held in a neutral position while breathing and while moving the arms and legs in motions that mimic the functional ways the core will be stressed in a given sport or activity."  It is not about who can complete the most crunches in a day or buying the latest ab lounger, but instead; one has to bridge science and sport to properly enhance core stability.  I have a couple of examples below of core stability exercises specific to the sport pictured above them.