Highest rating gain for me was learning enemy cooldown names

I stopped blaming every loss on balance when I learned what the other team was actually pressing. Trading trinket or a wall into nothing was losing games before the real go happened.

Cooldown literacy is huge. Even healers who know PvE timers can miss that arena damage is scripted around setups, not boss bars.

Watching one replay and naming every major offensive usually teaches more than queueing ten angry games.