I've never posted in this thread before but I have just have to vent-no other game in my entire life has frustrated the fuck out of me like this game. I just suck. I've spent money for cards, got a few Legendaries, I read up on strategies, understand the mechanics, watched streams, etc.
No matter what, I always blow. My enemy always has the exact card they need to ruin me. Every play. I'm just so defeated. This game just depresses the ever loving fuck out of me. I just wish I was good.
Playing a certain deck isn't that hard, it requires a little bit of matchup knowledge and understanding how your deck creates a win condition (contrary to what some people say here, thinking that piloting is something outstanding).
A big part of the game lies in what deck you run. If you don't have most of the cards, you also pretty much forced to either spend some dust, or create a deck with what you have.
The latter is how I play the game, and still do because that's the most enjoyable part of the game for me. For each daily I create a new deck and test and tweak based on wins and losses.
The question is, what deck do you run? If you're using a deck that 90% of the other players run, then it's kind of impossible to have a terrible win rate, since those decks pretty much play by themselves. So I assume you make your own decks.
You have to ask yourself: what is the win condition of your deck?
Does it continously dominate the board?
Does it have some removal for a swing around?
Does it have high unexpected burst damage?
You'll notice that these themes always come back in other decks. A deck that usually just wins with many minions usually has almost no AoE spell or that many big minions.
A deck with a lot of taunts and spell based removal is usually trying to turn the game around in their favor by using higher value (per mana) cards.
A deck that wants to draw a lot is probably going strong combination of cards, usually for instant burst damage.
When you play a deck, you have to know what the win condition is of your opponent and of your own. Based on that, and understanding what cards are likely to be in your opponents deck if you see a certain opening, you should set up a game plan on the fly.
A simple example would be:
Against a mage playing a minion every turn, you want to respond fast with your own minions and spells (likely aggro).
Against a mage who has used his four first turns just to draw, you want to do as much minion damage before turn 6, but then slow down the amount of minions you play (likely a freeze mage)