Attacking in Chu Shogi Part 1: Flank Attacks

For a while I've wanted to write something about where attacks come from in Chu, and how games are won especially, be it brilliant attacks or terrible blunders.

1. Attacking on the Flanks
This isn't usually the slow advancement of generals but rather a combination of generals supported by major pieces and conflict between major pieces. Against a strong defense made up of generals, it is obviously necessary to exchange off a majority of the defensive pieces before any progress can be made. This leads to multiple important concepts: The clearing of the 3rd rank from last is not just a helpful side effect of proper development. For the defending side, a clear 3rd rank should be used to position all orthogonal ranging pieces (rook-type pieces) + VMs to support the defending generals. Without this defensive coordination, the attacking side would just be able to clear everything off and break through. A mass of poorly supported weak pieces is the Chu Shogi equivalent of bad shape in shogi or go, as would weak pieces in the wrong positions. Because all the generals have different movements, they work best in certain defensive or offensive positions. The attacking side also needs a clear 3rd rank to effectively fight for control of files. 

 Additionally,  numbers matter. To attack effectively against good shape, you need the same number of generals or more, and you also need to time any exchange, especially pawn exchanges, so that it achieves the maximum effect, i.e. you should be fully prepared, with your pieces maintaining good shape afterwards. Not all exchanges are effective, and when you capture a pawn and let it be recaptured by a piece of the opponent, you are losing a tempo, by dragging an opposing piece forward. You must gain something in return. For example, on move 137 of this game, the best move was not what was played, an exchange that loses tempo, but instead to attack on the edge file to weaken the opponent's shape or force them to capture the pawn themselves, or to create space for maneuvering by pushing the go-between. 

What is Good Shape when Defending?

Later in the same game linked above, Sente was able to break through on the left side of the board, by removing the defender of a copper general. The setup I used there, with a copper and leopard side by side is common out of the opening, but opening positions are not fixed and have to be modified to fit the board position. Two generals on the same rank which do not defend each other, against a frontal attack, are bad shape, and this bad shape cost me significantly in that game. Good shape when defending is solid shape, that cannot be broken so easily. 

What is Good Shape when Attacking?

Attack in the moment has only one goal, speed. Therefore tempi are precious, and pieces have to cooperate to avoid being separated and allowing a counterattack. In the endgame, attacking shape can be destroyed by ranging pieces that have much greater freedom of movement in such an open position than weak generals. Therefore good shape in attack also does not lead to an overextended, useless position in enemy territory once endgame comes. Significant weaknesses left behind need to be kept under control whether an attack succeeds or fails. Again, the same game shows examples of this. 

One final note: Chu Shogi isn't a game that can be rushed, and even openings such as Go-Between Exchange only theoretically have the goal of gaining an advantage when the dust settles, converting that advantage (which is of course not proven and just in the eye of the player) in the full-length middlegame that follows, so patient development and improvement is important no matter what sharp openings you play.