I would say personally Ankain had a small advantage in the fight. When Obi-Wan said "It's over Anakin I have the high ground," I believe he said that not because he actually meant it but to stirr up Anakin's rage. Because he knew that by saying it that way Anakin would want to prove that just because Obi-Wan has the high ground doesnt mean anything to him, and that he is so powerful he can jump over Obi-Wan and continue the fight.
But Anakin in his own rage didnt realize this wasnt possible, and instead of being careful and even doing a small jump he wanted to over do it, to show he had superior power.
My interpretation anyway