Brooks-Baker was not known for the reliability of his information. His obituary in "The Daily Telegraph" would say of him: "His great advantage for journalists was that he was always available to make an arresting comment; his disadvantage was that he was often wrong". Critics of the theory point out that perhaps a third of all Americans may be descended from John, King of England (ruled 1199–1216), and that the odds of being distantly related to other royalty are even higher. This is an effect of a phenomenon known as pedigree collapse which occurs due to the doubling of the number of a person's ancestors with each generation. In theory, each person has over one thousand ancestors after ten generations and one million after twenty, far exceeding the number of persons actually living in most regions at any point in time. In fact, most people are descended from the same ancestors multiple times through different lines while anyone living at the time of King John could have tens of millions of descendants in the present day.