Am ranking a site in a very competitive niche and was ranking top 5 for about 10 phrases, am a risk taker decided to change the title tag, shortened it. I know this can mean two things. Increase in serp or decrease in serp. After the index of the title tag, Google reshuffled and sent all ranking to never land. So please if its working leave it be, don't take huge risk like me, It might go a huge way for me, but this time my gambled failed, Done it many times with positive, but today got negative from it.