Let's say you make a free form artisan loaf with all purpose flour and your hydration is 85%. The next time you bake you use bread flour. Now if you use the same amount of flour (the same hydration ) you will have a stiffer, drier dough. So how do you adjust for the greater capacity of bread flour to absorb water? Is there a factor -- 1.1x or 1.2x or whatever? Or is it just trial and error?. Certainlly, going by just the "feel" of the dough is chancy.