The advantages of open lines are self-evident. Except horses, cars, elephants and queens all move in a straight line. Open lines can help you attack quickly. Especially the vertical line opening, because the power of the "overlord car" (two cars that protect each other) is far better than a queen in the line opening, which is why the line opening should be started as soon as possible in the middle game. It can be said that opening the open line is the first priority after Che Wang completes the translocation.

The seventh horizontal line is close to your bottom line. After the soldiers on this horizontal line can be upgraded quickly, if you don't have enough defense on the seventh horizontal line, the situation will deteriorate or even reverse in actual combat because of the upgrade of a soldier. In addition, according to the theoretical analysis of some experts, Wang is generally close to the bottom line (except the endgame). Therefore, when the opponent's hadron enters your seventh horizontal line, it means that your king is likely to be exposed to the threat of the opponent's son, so you should be vigilant to prevent the opponent from a coup or lightning strike.

The strong case is aimed at image and position. Because elephants and queens (generally speaking) both move diagonally, if your elephants or queens can cross each other's chains, the squares where you and queens are located will be strong in color. For example, when the opponent's soldiers are all in black squares, then when you have white squares, your strong squares are white squares.

The principle of bad elephant is similar to that of strong elephant. When your elephant can't fight because of the chain of the other soldiers, or your elephant can't form effective fighting capacity because of the chain of your own soldiers, this elephant is called a bad elephant.