The Japanese suffered 30,000 dead and an equal number wounded in their effort to take northern Shanxi. A Japanese study found that the battles of Pingxingguan, Xinkou, and Taiyuan were responsible for over half of all the casualties suffered by the Japanese army in North China. Yan himself was forced to withdraw after having 90% of his army destroyed, including a large force of reinforcements sent into Shanxi by the central government. Throughout 1937, numerous high-ranking Communist leaders, including Mao Zedong, lavished praise on Yan for waging an uncompromising campaign of resistance against the Japanese. Possibly because of the severity of his losses in northern Shanxi, Yan abandoned a plan of defense based on positional warfare, and began to reform his army as a force capable of waging guerrilla warfare. After 1938 most of Yan's followers came to refer to his regime as a "guerrilla administration".