If you accept the argument that mental strength has to do with fighting spirit in line with reasoning, read here and here and here. If you also accept that our assumptions determine our conclusions which in turn become building blocks for other assumptions, and if those assumptions are faulty then we can arrive at strange conclusions, read here. And if you further accept that much in life are illusions and have nothing to do with the essence, the substance, read here.
If you accept the above, then these articles start to make a little more sense — Read here and read here.
From the above I hope that I have demonstrated that the road to that GM needs wider consideration. The substance is determined by understanding ourselves, our opponents, the board and the clock. Understanding ourselves is not an easy journey for much is illusion. The point of mental strength for instance. Nature vs Nurture. Nature can give you IQ, a predisposition to certain styles, that is a gift. But nobody is born with mental strength. This has to be built step by step and through rigorous and correct training. Tough but fair evaluations must be made and the real separated from the illusions.
Time itself is illusory. Ever played chess and wonder where the time went?
And so I argue that while it is not easy to build that GM, it is very easy to destroy anyone with potential. Fixed tournaments, lack of acknowlegement, allow the players to conclude that they are helpless. Especially the young ones. Read here and read here.
So if we really want that GM, we all need to be part of the solution.
The above also tell us that we need to also see further than the 64 squares. Or I hope I have at least presented enough for you to consider my points. For that GM lies at 1000 meters below. And so it follows that development of mental strength needs to be included in chess training. Read here.