An early 20th century Chinese timeline, written by CCA. It can be read here.
The author of the TL got the idea after reading Jonathan Fenby's book Generalissimo Chiang Kai-Shek and the China He Lost, in which he found a mention that Chiang was considering going to Germany in 1912 to 'further his training'. Hence, in 1912 Chiang Kai-Shek shoots a rival of Chen Qimei dead. Fearing retaliation he decides to flee to Germany and tries to enlist in the prestigious Prussian Military Academy. This is the POD - in OTL, he decided to flee to Japan instead.