This is when you start and form your pieces for attack and defense. The aim of this phase is to position your pieces for better attack and stronger defense. You will also choose which opening strategy you will be using. For this, knowing Joseki (定跡=system opening moves) will help . Capturing and exchanging of the pieces will be minimal at this stage.
This phase is when you initiate your attack moves and exchange pieces, hopefully to your advantage. You will try to converge where your opponent's King is. You judge the situation with the position of your pieces and also with the value of pieces you have on the board and on hand.
This phase is when you will try to checkmate (詰み=Tsumi) or
brinkmate (必至=Hissi) your opponent's King. The value of pieces at hand
is not as important. Speed to which you close in your opponent is a top
Balance of Komagumi (駒組み)Formation
In the beginning of the game when you are moving your pieces (getting ready for an attack or something), there is a universal rule about the ratio of pieces to use for each task. See the diagram below.
Player 1's formation is "Yagura.(矢倉)" Player 2's formation is "Shiken-Bisya". (四間飛車)
In Each case, King is protected by one Silver and two Gold pieces. A Knight and a Lance closer to the King also compliments each players' "Kakoi (囲い=Castle or Fortress).
For your attack group, there is a Rook, a Bishop, one Silver, and a Knight. A Lance may or may not be a part of the attacking force. As you can see here, popular systems such as Yagura and Furi-Bisya seem to stick with this assignment of pieces. In general,
- Attack with a Rook, a Bishop, a Silver and a knight (+ a Lance) for an effective strike.
- Defend your King with two Golds, a Silver, a Knight and a Lance.
Trap of Komagumi (The story of building a castle in front of a cannon)
You may not blindly arrange your pieces and ignore what your opponent is doing. The diagram here is a good example. Player 1(Sente:先手) has built a nice Yagura castle. However, Player 2（Gote:後手）'s formation is "Yagura Kuzushi"(矢倉くずし=Yagura destroyer) This "Migi-Shiken"(右四間=right wing fourth file ranging rook) is specifically designed to destroy Yagura castle. The next diagram shows this castle is already in jeopardy, just after 3 moves.
Note that Player 2's Bishop is directly threatening Player 1's King.
Clearly, you need to modify your tactics according to your opponents move. In this diagram Player 2 (Gote) is winning.