Ele sham - BGB Tips?

I’m like 1950 mmr in solo shuffle, but float 1500-1800 mmr in BGB. I must be doing something wrong, I’m 2.4k BGB on a hunter and disc priest - what can I do to improve on Ele sham?

Do I need to stop spending so much time flame shocking multiple targets, I can’t carry these BGB games like I was able to on other specs. Any tips from Ele shaman kings out there? The goal is to hit 2400 on a new class and spec each season - this is season for my shaman!