Assist points

I think everyone knows this:
You are fighting against some enemys, make them alot of damage and a Ahmedmido comes around the corner with his 200 ping and thompson and is stealing him. After the round finishes youre seeing, that you made him 90+ dmg .
My solution:
For every third kill steal above 75hp u should get a kill, and for every steal above 95hp the kill to. If someone played battlefield 4 he knows what I mean, maybe a message could pop up like;, damage counts as kill,, or something like this.