One oddity of seat tube angles is making bikes for tall riders with 72.5 or 72 degree seat tube angles, and for short riders with 74 or 75 degrees. This is not because tall or short riders have different femur proportions, it is because, traditionally, everyone uses crank lengths in a very narrow range of lengths. So to maintain the KOPS (Or there about), a tall rider needs to push the saddle further back, and a shorter rider forward, following the disproportionate crank length.

With my 37" inseam and 200mm cranks (exactly proportional), 73 degrees runs right up the middle of the saddle. I have one at 72.5, which puts the clamp near the back of the rails. When the saddle is that high, the angle adjustment range that the saddle rails provide is not much.