Could you name your 5 best heroes at the moment? Most of the times there is always atleast 1 that almost always works. I coached a rl friend from silver to I think platinum 3 by just playing a few QM's with him while he played his top 7 (he said he had 7 comfort picks) and finding out he was way better with Gul'dan, Valla, Kerrigan and Li Li than he is with any other hero in the roster. This is a good starting point since Valla and Gul'dan are almost always one of the best choice and with Li Li you have a good 2nd support which is quite strong at the moment. From here on he always started a Hero League match with saying he was only really good with those 4 so it would help if someone else could tank/heal because he was just not good at it and it will cost them the game. Abit dramatic, but it did help. He was able to play his 4 best heroes in 89% of his games since then with a win percentage of 68% and went from silver 4 to platinum 3.