phew--- that took me some searching.... :)
leon-- this is a link to a flyball site... I don't compete in the sport myself, but I think this site does a *really* good job explaining some of the fundemental training concepts (like the variable reward piece I was trying to explain-- it's explained quite well in Chapt 5). It's long-- but packed full of good info (in my opinion).
http://www.flyballdogs.com/on_mark.html
-chloe