Virtually all aspects of the Augur oracle design were originally proposed by me. Yet, it was not possible without Joey. I continually pitched ideas most of which were bad ideas and I needed Joey to detect bad ideas. I came up with the formulas used and wrote proofs for why they were the minimum value transfers needed to make honest behavior rational. Jack did not participate in the system design (cant remember if literally zero or a little bit…he was following along closely). The system design was Joey and I, with a small amount of help from Vitalik via Skype.
Eventually I noticed Micah Zoltu on Augur forums and advocated to have him hired. At the time he was on par with me at decision theory / mechanism design, but better than me in every other measurable way. He replaced me and finished out the final tweaks of the system design.