I've been lead to understand that some issues may have been before Tycho Brahe no one had made accurate measurements, especially of the entire tracks across the sky, not just 'interesting' places.
"Kepler realized that Tycho's work could settle the question one way or the other, so he went to work with Tycho in 1600. Tycho died the next year, Kepler stole[sic] the data, and worked with it for nine years.
He reluctantly concluded that his geometric scheme was wrong. In its place, he found his three laws of planetary motion"
