Big Spear Liu Dekuan was a famous martial artist of the older generation. Jin Jingzhong wrote about him in Famous Martial Artists. What we have heard comes from Liu Zhonggang, Li Ziming and other old martial arts teachers.
Liu Dekuan's original style was Yueh Style San Shou (also called Yueh Style Eagle Hand or Yueh Style Connected Fists). He learned this from Hebei Xiong County Liu Shijun. De Kuan first studied with Shijun's student Xu Liu and then later he studied with Shijun. Shijun's spear methods were excellent, Dekuan continued the tradition. He also used the big spear, for which he is famous.
Liu Dekuan's original school of fighting was not inferior to other schools. Its founder's were already famous. However, he roamed around curiously looking over many schools and he learned many arts. In Beijing, he got to know Dong Gong Haichuan's student Cheng Tinghua (Eyeglasses Cheng). Cheng was in contact with a comparatively widespread group of teachers. He and Xingyi's Li Cunyi and Zhang Zhaodong were good friends and mutually learned from each other by exchanging views. He caused this commmunity of famous teachers to accept Liu Dekuan as one of them. Each one in this group had their strong points. Their fighting skills were equal and almost on par. Dekuan was drawn into Bagua System through the Cheng Style, and assisted Cheng Tinghua in expanding Bagua System everywhere.
Liu De Kuan also contributed to the Bagua System. Cheng Style Bagua students train the Six Lines of the Halberd. This comes from Liu De Kuan. Liang Style of Liang Zhenpo's student Guo Gumin in his compilation of martial arts material says, "All the elder teachers got along with Mister Liu Dekuan. In the course of time, all was made clear to him, and he ultimately was enriched." And, "He toiled to get pointers from the older generations." Li Ziming also says, "Guo Gumin followed Liu Dekuan around, thus searched to get secrets of the Bagua martial arts."
Cheng Tinghua's eldest son, at one time, was teaching the art in a field
outside the Suiwen Gate on Ximo Street. Famous practitioners from
both Yin Style and Cheng Style Bagua often came in their free time to sit
and linger. At this time, Big Spear Liu, in his old age, suffered
form an eye disease. Both of his eyes were not bright. However numerous
students still wanted to compare skills with him. They only needed
to bring the shaft of their weapon in contact with Liu's spear shaft to
try to lift it up. Liu would stick to their spear shaft and advance.
The opponent would lose his weapon and be thrown by his strike. One
can see how his spear art was pure.