I'm gonna suggest two things to you. These are just my opinions, but they're sorta backed by fact. Alright, so first of all, the deck count. You should try to find a way to cut the fat of the deck that you don't need to bring it down to 40. Upstart Goblins, for example, aren't useful in a deck of over 40 cards. Simply because an Upstart Goblin is basically an empty slot that lets you draw a card, so in a 40 card deck it'd make that 37 cards, which is amazing. But in a 47 card deck, it'd only make it 44. You could achieve that by just taking out the Upstarts entirely so you don't end up giving your opponent life points.