Originally Posted by Reynolds
IF the seat tube angle is 'normal', and IF the rider has 'standard' leg measures, and IF the seatpost is standard setback, generally the saddle must be all the way back to achieve KOPS, in my experience.
Depends a lot on rider height and frame size. It is pretty common to see pro racers with their saddles all the way back, but they often ride small frames with more aggressive geometries than most recreational riders.