Fritz Trainer Middlegame - Adrian Mikhalchishin: The Secret Weapons of the Champions Modern middlegame theory does not exist in written form. That is why players and trainers have to go back to the old recommendation by Nimzowitsch to study typical positional methods the key to understanding the middlegame lies in understanding how to execute certain positional manoeuvres. Mikhalchishin explains, for example, Botvinnik's famous "rank against centre" strategy, which is one of the corner-stones of positional play Also Petrosian's white square strategy is an extremely important form of the control of squares and space. Tal was a great master of changing the material balance in every position  for example, rook and pawn against two pieces. GM Makogonov, once a trainer of Vassily Smyslov, invented the famous secret positional rule of the Soviet chess school. How and when it is possible to apply this method you will find out from this disc.