We have use case to add engagement score which will be present inside the result to the elastic score. The engagement score will be between 0-1. We want the engagement score to make a significant contribution to the overall score. So, if elastic score is some thing like 6 or 7, then engagement's contribution will be relatively low. So, we want to make elastic score also between 0-1 so the overall score will be between 0-2 and both elastic score and engagement score will have equal contribution to it. We want to do this during index time.