GM Tony Miles vs GM Ulff Andersson
Las Palmas 1980

 

Chess players must have faced similiar position as diagram below, many times.
Let diagnosed the position carefully. Black has just play 20…Qxh6. In my opinion, in this particular position , it’s not worth to analyzed in term of candidate moves, the imbalance factors , the threat or other factors because white obviously must take the black’s queen on h6 . White have two obvious chooise which is i) 21.gxh6 or ii) 21.Rxh6…
In analyzing this type of position, Mc Donald suggest the use of GM Siegbert Tarrasch approach (photo right) :-

“weak points or holes in the opponents position must be occupied by piece, not pawns”

So, in position above , white must play 21.Rxh6! because if 21.gxh6? the weak black square on h6 is more or less can’t be occupied by white piece anymore because and more thing, white have block the h file with his own pawn which block his major pieces ( queen or rooks) to pass trough.

21…Rff8

22.Nd7 ! One Golden Rules of Chess Strategy by GM Neil Mc Donald is a piece who has occupy an good square should search for better square !