... All GMs indeed have study a lot of openings but none of them took the title because of the opening.They would take it anyway while others can't be CM even if they memorise all the lines of opening theory.Why is that?Which is the piece that is missing here? ...
"If you want to improve in classical ( slow ) chess you have to work on all 3 phases of the game . ..." - NM Reb (August 30, 2017)
"Yes, you can easily become a master. All you need to do is some serious, focused work on your play.
That 'chess is 99% tactics and blah-blah' thing is crap. Chess is several things (opening, endgame, middlegame strategy, positional play, tactics, psychology, time management...) which should be treated properly as a whole. getting just one element of lay and working exclusively on it is of very doubtful value, and at worst it may well turn out being a waste of time." - IM pfren (August 21, 2017)
The player who understand opening principles and he is a beast in tactics and endgame can play any opening with proficiency because he can calculate better and his evaluation is more accurate than his opponent who only concentrates on opening.