Well, wrt chess, we can have dueling GM quote battles over this point:
From "Andrei Istratescu's top 10 reasons for stagnation:"
1) Too much play
Playing chess - practice - is very important for improvement. When you play chess (over the board, at tournaments), you put into practice what you have learned, you use your brain to think chess, you are in the testing environment, you test your accumulated knowledge and skill against another person.
However, too much play and too little study holds you back. You can repeat the same mistakes over and over. You will tend to follow your own old patterns and not have time to develop a different, correct thinking process, and to learn proper strategy and new ideas.
In this case, you should take a long break from playing and concentrate only on study for several months. You will make a significant improvement.
In my experience, the first chess book I read (Logical Chess, Move by Move) probably bumped my rating by 400 points. Then, more specialized openings and tactics books another couple hundred. After that, simply playing got me mostly nowhere.
From "Andrei Istratescu's top 10 reasons for stagnation:"
1) Too much play Playing chess - practice - is very important for improvement. When you play chess (over the board, at tournaments), you put into practice what you have learned, you use your brain to think chess, you are in the testing environment, you test your accumulated knowledge and skill against another person. However, too much play and too little study holds you back. You can repeat the same mistakes over and over. You will tend to follow your own old patterns and not have time to develop a different, correct thinking process, and to learn proper strategy and new ideas. In this case, you should take a long break from playing and concentrate only on study for several months. You will make a significant improvement.
In my experience, the first chess book I read (Logical Chess, Move by Move) probably bumped my rating by 400 points. Then, more specialized openings and tactics books another couple hundred. After that, simply playing got me mostly nowhere.