The personality of a dog is flexible and indeterminate. Dogs can be exuberant or shy; friendly or hostile; fearful or bold; aggressive or passive or some combination of the above. These differences in personality may to some extent be determined by breed, or individual genetics, but for the most part it is based on how and to what extent each particular dog has been socialized.
If you are wondering why some of the previous years' top placing dogs can't be found in the current year's top placings, it MAY be because they have been placed in the "T" Category listing at the BOTTOM of their Class!!
Everyone is familiar with sit, down, and come and other similar commands that are standard fare in the general obedience training class. The novice handler might not be familiar with what competitive obedience looks like or realize that it’s really just a continuation of those basic skills.