Okay I must be missing something, how does the seat to bar drop vary from saddle to saddle. The way I see it is that the top of the saddle should be at the same height regardless of what saddle you are you using. So if the top of the saddle is the same height, how would it affect the saddle to bar drop? I'm sorry I must just be missing something.

But here is my example. You have a brooks b17 and a turbo. The top of the saddle should be about the same height for a certain rider, so if the top of the brooks is lets say 6 inches above the top tube, and the top of the turbo is 6 inches above the top tube, how does it affect the saddle to bar drop?