huh? i've seen i think one or two that, well, doesnt prove it but it has a vey high possibilty of the 4th being naruto's father. it was when naruto summoned the frog boss or something and after that the frog said that the last person who ever rode his back was the 4th and that he was surprised. so i think that that is a BIG clue. naruto also had that power to summon the frog boss ninja harhar