Prestige guide ( rank up system ) Number Of Downs

Hi guys ,,

My friends told me if you have many downs such as 1000+ down

It's gonna be very hard to rank up to skull and knife

Because 1 downs takes 150 kills or 250 or 300 NOT SURE

I don't know if this is true but I wanna know

Does the downs number affects the prestige system and decreases kills

Cuzz I got 80000+ kills with 1553 down

Is this the reason I couldn't rank up to skull and knife

ANY IDEAS