A little bit lesson for rookies :  the middle of match...

(be tolerant for translation)

Player must assess his position, develop plans based on the forces.

If you have a development advance (3 pieces against 2 for example), start something and open the game. Conversely, if you have a developmental delay, No activities, keep the game closed and try to catch up. 

  If you have more pieces, exchange (at the end you will have a piece against nothing), if it is you who are late, move and avoid the exchange, nothing more logical! 

The middle game should try KO while mating the king. So ... we search a strategy ... and what a strategy? This is the big idea. And the tactic : the method to make it.