Board Thread:Theories and Speculation/@comment-33186873-20180115161559/@comment-25122992-20180120190852

@BlazeRelease, well, there's some evidence that Madara kept an eye on Obito for a while and didn't just found him by accident. During the Hidden Mist shinobi massacre, Zetsu himself mentioned that Madara "choose" Obito, and when Madara admitted his role in orchestrating Rin's death, he noted that he knew quite a lot about Obito's personality before the incident (such as his habit to help the elder people).