Joe,
Oh, sorry, you wanted the serious answer!
Well, imagine the point at which the ankle lever pivots, and how moving this effects saddle height. Take a guy like Lance Armstrong, or Fausto Coppi who both ride in a serious "toes-down" pedaling action. I would imagine that they require a full inch extension over someone who pedals with more of a flat foot, or has smaller feet, given the same action.
Grant McLean Toronto, Ca
Joe wrote: Actully, my "foot thought experiment" was directed to Richard Rose as a credible response to his question about frame size. And as I responded to another CR member earlier, "Foot size is often a wash, I guess you could call it a dynamic consideration, because for the same reason the cycler changes hand positions on a ride, he often ankles differently, as in heels first up hills and such."