I play terribly all of the time, there are very few games I go back an look at where I don't feel I made any mistakes at all. I'm sure other "top players" will say the same thing. And most of the time these misplays are tactical things -- not the kind you're talking about. Little ways I could have played my turn better or ordered my buys to make things move along quicker, or reduce the chance of bad things happening to me. Sometimes I catch these things while I'm playing, but a lot of the time I only see them on the replay or when someone in chat tells me about it. I'm quite sure that if someone looks at their play closely enough, they will find tons of these, everywhere. In most turns of almost every game.
Yeah, that was not what I meant with "terribly". I was responding to Mic Qsenoch, who has clarified more what he meant with "terrible".
Maybe your definition of "terribly" is something I'm not picking up on, but any misplay (even a small one) is a chance for me to learn from it. Maybe you don't find any benefit in looking at your past games closely, that's OK.
I do, and I don't think I said I don't. I just said you should also consider how much of it is luck. That's the first thing to figure out. If it's mostly players' decisions, and especially if it's strategic decisions, there is something to learn from the progression and outcome of the game. If it was mostly luck, it's difficult. If your view is that it doesn't matter (to be able to learn from it) how much of it was decided by luck, then that means it doesn't matter how it turned out in the end, which means you could just as easily learn by looking at the kingdom before the game starts. On the other hand, I can only learn from a game by playing it. That means seeing how the game progresses. To make it extreme, if I choose strategy A and you choose strategy B, and shuffle luck completely sabotages you on turn 4 and I have smooth sailing, the progression after that doesn't tell me much about which strategy was better (unless your strategy was so good that you won anyway of course). If it tells you just as much as if the luck were more or less equal, then I don't understand why you need the actual game at all.
You can say it's true, but I can say it isn't true (or at least that I don't know that it's true, just to give you the burden of proof 
) but both of us are just saying things based on our guts and not on actual knowledge. That number (50%) was effectively pulled out of thin air, I can pull a number out of thin air too and say it's less than 50%.
Yes. It's just my impression that it's more than half.
If you believe this is the case, then I'd say you need to work on getting better at learning. When I start a thread to talk about something and get feedback, my takeaways aren't specific moves I should have done better that game, it's assumptions about the way I play the game that need to change. Do I need to adjust in my mind the power level of a card or a pair of cards? Do I need to put in a mental note to slow down at a certain point in some games? (Never press the "play all treasures" button in a Farmland game. Just don't ever do it before thinking about what you're going to buy.) Or maybe I just need to play a bunch of games with a card or two cards or something to get a feel for something. It will be different for you but if you can't learn from your past games, maybe try learning a different way? I mean, you describe this problem and that just doesn't register with me so maybe it's on your end. I'm sorry but I feel like this isn't really helpful, what I'm saying here. 
Firstly, see above. Secondly, I'm not asking for help. I can learn from past games, some more than others. I learn less useless things by identifying that in some games what happened was decided more by luck than by the players' decisions. That's all I'm saying. Identifying that, and then also analyzing decisions in the correct way and learning from that, is difficult and I'm not saying I'm great at it. You might be better at it than me. But that would mean you're doing it, maybe without realizing it (or wanting to talk about it, like you say).
I see how when players ask for help in finding out why they lost, everybody just ignores the obvious, like, "your Mountebank missed the shuffle every time". Instead they focus on these minute details of decisions that might be correct, but that play a minor role unless both players have exactly equal luck. (Sometimes these small decisions might make or break a game, but in my view that doesn't happen that often. But over a big bunch of games, the player who makes more correct decisions will win more games.) Anyway, my point here is that I think that to tell beginner or medium players to ignore the role of luck in a given game and just make them think that they make their own shuffle luck, is bad advice, because it implies that if they lost, it was because they played badly. Sure, there's always stuff you can learn from every game by having better players analyzing your play, but that is true of all games, whether you won or lost.
