I haven't watched your games, but it's very likely that you're finding the correct strategies and executing them poorly.
This doesn't mean you're a bad player, because pretty much everybody executes strategies poorly. Some people just execute them less poorly than others. Sometimes, this means reordering cards revealed by Cartographer incorrectly. Other times, it means making a bad call on whether to trigger a reshuffle.
Let's put things this way: suppose we replaced your opponent with a bot from the simulator. This bot makes the exact same buy decisions as your high level strategy, but follows these play rules:
- play all Action cards that give +1 Action or more
- play as many terminals as possible
- play all treasures and buy something
Then, I'd say you should be able to get at least 55-60% win rate against this hypothetical opponent, depending on the board, because all those micro-decisions from deciding when to reshuffle, how to build a deck when you're behind vs ahead, different sequencing of actions, etc. should add up to an advantage for you.
Now, that's a bit of a pointless hypothetical, but here's the more interesting corollary: if you decide on a worse strategy, but execute it extremely well, you can still beat a stronger strategy, or beat bad luck.
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At the start of the game, you want to ask yourself what your ideal deck is going to do. This could be "play a Butcher every turn", or "cycle through lots of cards with mass Stables, with one +Buy to pick up more Stables", or "hit $8 every turn using mostly treasures". Then, make sure that every buy goes towards that goal. Every deck should have a focus/lynchpin that it's founded on - if you can't say what you want your deck to be doing, you're gonna have a bad time.
If your crazy elaborate engine doesn't come together in time, then oh well. You at least have a crazy elaborate half-engine, and maybe you tone it down a notch next time and build a more modest engine. It's better than starting with a crazy elaborate engine blueprint and ending with a modest flower pot with a half-finished rocket booster instead of a flower.
Look, I lost the metaphor a while back. Bottom line, I think committing to silly, harebrained ideas and pushing them as much as you can tends to make you a better player, since it gives you an appreciation for when simple things are better, while leaving yourself open to crazy nuttiness.
I...think that was entirely different from the point I was planning to write out when I started this post, but oh well.