Unless a player has an 'understanding chess' rating of at least 2400, the amount of significant knowledge that he can impart on others is limited.
One of the objectives of opening play is to try to surprise your opponent.
Once you are in the endgame, the moment of truth has arrived... The amount of points that can be gained (and saved) by correct endgame play is enormous, yet often underestimated.
In Chess, at least, the brave inherit the earth
The number of 'unneccessary' errors that have been committed on move 41 are legion.
Only play into a variation in which your opponent is strong if you have your own personal novelty ready!
Even when the time control has been reached, there is one situation where you want to act as if it has not: when your position is absolutely lost.
The key to ultimate succcess is the determination to progress day by day.
After a bad opening, there is hope for the middle game. After a bad
middle game, there is hope for the endgame. But once you are
in the endgame, the moment of truth has arrived
You must be able to handle a variety of move orders during the first 5-6 moves - otherwise you'll find yourself 'tricked' time and time again.
Your practical results will improve when you play what you know, like and have confidence in.
Bobby Fischer started off each game with a great advantage: after the opening he had used less time than his opponent and thus had more time available later on. The major reason why he never had serious time pressure was that his rapid opening play simply left sufficient time for the middlegame.
Playing without a concurrent critical review of one's skills will simply get you nowhere.