After World War II, the communists, led by Mao Zedong had many advantages. They controlled the important areas of eastern China and around a quarter of the land.  A very important strategy that Mao Zedong utilized was to win favor with the peasants, which were an overwhelming majority of the population.  He promised that he would create reforms that would improve their lives.  For this reason, Mao was extremely popular.  Unemployment and other economic difficulties in Nationalist-controlled areas were making their leader, Chiang Kai-Shek equally unpopular.   So with popular sentiment on the side of Mao, he planned and coordinated a very cautious strategy to win the war.  He would concede land to the nationalists in instances where his forces were outnumbered.  In this way, he was able to preserve the number of troops fighting for him rather than wasting them in battles they could not win.  Support, in the form of weapons from the Soviet Union, was also an important advantage that Mao had.  Much of the financial support that Chiang Kai-Shek and the Nationalists received was wasted through corruption and mismanagement.