A possibility of insurance on ranked promos?

I strongly feel as if there needs to be at least some form of protection in promotion games simply to prevent games that were lost due to something uncontrollable such as a feeder or a dc. Promos are supposed to look at an individuals ability to play league to decide whether they should be eligible to promote to a higher decision, which is extremely awkward in a team focused game. While teamwork is an important skill having a single player dc 7 mins in or go 1/15 feels as if nothing could be done about it. Such an occurrence would be hard to do automatically, as there could be hard to notice variables which leads this, such as you flaming someone to disconnect. regardless, something simple such as doing well (A or up) in a team that is not doing so well should be implemented (if not already is) to protect from these shitty games.