"Obedience Trials test a dog's ability to perform a prescribed set of exercises on which it is scored. In each exercise, you must score more than 50 percent of the possible points (ranging from 20 to 40) and get a total score of at least 170 out of a possible 200. Each time your dog gets that magic 170 qualifying score, he's gotten a "leg" toward his title. Three legs and your dog has become an Obedience-titled dog! There are 3 levels at which your dog can earn a title and each is more difficult than the one before it. You may see levels divided into "A" and "B" at a trial; "A" classes are for beginners whose dogs have never received a title while "B" classes are for more experienced handlers."