Dream of your dead grandfather and the number is 47. If he speaks to you, it becomes 48 instead. And if, in the dream, he mentions something specific, an address, for instance, or a date, that number may be worth playing, too. The rationale is pretty simple: the dead are traditionally considered reliable informants, so ignoring what they tell you would be a waste.
This is, in essence, the smorfia napoletana: the system through which Neapolitans have for centuries translated dreams, people, objects and events into numbers to play in the lottery. The system runs from 1 to 90 because the Italian Lotto itself uses ninety numbered balls.
