Man bites dog
The phrase man bites dog is a shortened version of an aphorism in journalism that describes how an unusual, infrequent event (such as a man biting a dog) is more likely to be reported as news than an ordinary, everyday occurrence with similar consequences (such as a dog biting a man). The phenomenon is also described in the journalistic saying, "You never read about a plane that did not crash." It can be expressed mathematically; a basic principle of information theory is that reports of unusual events provide more information than those for more routine outcomes.