Dynasty mock draft grades

i have been doing mock draft for my new dynasty league start up as i have never done dynasty before i have bben using draft.thefantasyfootballers.com like the guys talk about for getting a draft grade and i have drafted what i believe to be unbelievable teams in the mocks using the udk dynasty startup rankings and i have gotten all “F’s” every time am i doing something wrong or should i pay no attention to the draft grades?? thanks guys

also any tips and tricks on how to win a dynasty start up draft i am all ears