In the game of Chess, pieces have specific quality in mobility and function on certain squares to entrap the King. Hence, quality of piece rank is significant to make or loose a game. In GOTG, all pieces can only move one square per turn regardless of rank. Since the flag position is variable and uncertain, quantity becomes more significant than quality of pieces starting from the middle towards end game stage. The initial clash on the front row attack phalanx supported by the second row defense phalanx must have brought you an advantage in quantity and a higher ratio of piece for piece.Your inventory of arsenal must have remained more untested pieces than your opponent's. If the opponent has spies left, you must have a few privates left. If your opponent has more generals, you must have at least one spy plus several middle ranks. If both of you has no spies left, you must have more pieces in total than his.
The essence of middle game stage is all about simplification.Simply challenge each untested piece on a per piece basis even if your opponent's strong pieces are guarding it. The more your opponent bluffs, the easier it will be for you to attack his bluffing piece. Manuever your attacking pieces such that when he counters by eliminating your attacking piece, you can still eliminate another piece with your next move. The rule of thumb is to eliminate and simplify all untested pieces in such that what is left of him will be a few tested pieces and the flag. Initiate separate attempts to cross your untested pieces on opposite sides to see if he will spread his cover and weaken guard. If he ignores you, move your flag across. If he spreads out to block, surround his untested pieces with yours altogether and choose which piece or pieces to sacrifice to entrap his flag piece.
Note: Be wary of over bluffing during the middle game stage as some bluff calls can put you at more risk than advantage. If your piece has already been tested, bluffing is useless and a waste of move unless your opponent is stupid. However with your untested pieces, feint weakness until the last moment. One purpose is to keep your untested pieces ratio greater than your opponent's. So long as your pieces are untested, you would want it to feint weakness to put him at a dilemma of where your flag position is. Feinting weakness also lures his guard down and gives him an illusion of winning. You may feint weakness and manuever yourself to a diagonal advantage and control. When the time is ripe and everything is in position, STOP FEINTING and SEIZE the enemy by surprise.