Grandmaster's Evaluation

In any given position a GM will have ideas. He knows what has to be done. This is because of the vast experience and knowledge. First he will find the strengths and weakness in the position. This will include the pawn structure, piece position etc. Every opening will have its own game plan. So he will know what has to be done in that specific opening. He will know the important games in the opening he plays and also the problems the players faced in that game. Come chess trainers would again and again recommend you to study top GM games. Try to figure out the moves played by the GMs. Calculate and assess the positions yourself and compare it with the GM's analysis.