1 physical quality
either strength, speed or endurance are too far
2 selection
just because of the power speed endurance of the requirements of the high, so the selection of material is very important. Yellow physical quality is generally worse than other races, so you must pick one in a million to select the quality of slightly better people, and then only on this basis to choose the reaction, tennis IQ good people, the equivalent of and Europe and the United States than more than the choice of a time, so it's difficult to find a good seedling.
3 due to the poor level of tennis, how to cultivate training are also do not know, purely blind, more unlikely to teach according to the material.
In fact, China's men's tennis level has been declining for decades, and in the 90s there was Pan Bing Xia Jiaping. All men's programs in China actually have the same problem.