Best strategy for (beginner's) improvement
"... White ... enjoys the advantage of the two bishops and controls the important d4-square, whilst his opponent's pawn-structure contains marked weaknesses on the queenside. However, if one tries to suggest a plan by which White can increase his supposed advantage, then one is pulled up sharp by unexpected difficulties. ..." - part of Keres quote in Chess For Zebras
... Chess for zebeas is a very bad book , not worth to be in any list. ...
http://dev.jeremysilman.com/shop/pc/Chess-For-Zebras-p3867.htm
https://www.chess.com/blog/soler97/quotchess-for-zebrasquot-a-review
... His examples were not examples of a player losing because of psychology.They were examples of a player losing from wrong evaluation which he wrongly attributes in knowledge and not in wrong knowledge ...
"... mostly I was working on the assumption that my two bishops and space advantage ought to count for something. ... I didn't look hard enough at the position in advance, and appreciate that the awkward placement of my bisop on c3 was indeed unavoidable. ... The most direct lesson concerns tournament psychology. Since playing this game I have noticed the following countless times: after playing a string of stronger players you come up against somebody with a rating similar or slightly below your own and you make the mistake of thinking of them as weak, and a chance for you to regain the ground you lost against the big guys. ... If you don't take them seriously on their own terms there is a big risk of losing further ground. ..." - GM Jonathan Rowson