Practice Doesn't Make Perfect
I have my own theory. The idea is that there are lots, lots and lots of tiny unspoken things which could make huge difference in long run. And those who successful doesn't necessary know their own tiny things they got right.Let's say there are two persons A and B who is training in chess. Person A trained for X hours and became chess master. Person B trained for 10X hours and didn't get even close to master level.The truth is that person A got some tiny unspoken ideas right (may be he even discovered them by coincidence). And person B got this tiny things wrong. No matter how much person B is training, he or she won't improve in chess until B find right way.Sad story is that A couldn't even realize what exactly he got right and take it for granted. So when A explains B how he train/play, he or she could say very high level things (which you can find in any grandmaster book) skipping huge unspoken context.That's why many people who read books written by chess grandmasters, don't become grandmasters. Chess grandmaster could try to explain you how he or she plays but these words has very limited power since unspoken context matters most.So if you didn't progress much in chess after learning theory and practising and reading grandmaster's book, it could mean that you just missed something very fundamental tiny thing which nobody speaks about. May be your spatial representation of how pieces move in the board is not suitable that's why for you it requires more computational power to imagine whole dynamics of some given chess position. May be if you play other similar games and then return to chess, you fix your spatial representation of chess in your head. May be even solving math geometric puzzles will help you with that.My point is that if you don't progress don't give up but don't bang your head against the wall. Instead think about more delicate things happen in your brain. Your goal is to find tiny thing in your head and fix it. I do believe if you find this needle in haystack, then you could make huge breakthrough.I think true intellect lies in metacognition. I mean how you think about thinking, how you think about learning.