Why is USA tennis in the doldrums?
On the surface, we have three, four or five superb tennis coaching organizations, under the USTA, USPTA, PTR, ITA, USHSTA, and more.
What is the problem? Basically, these above follow unnatural, faulty science and not follow some of the most elementary kinetics laws.
The most damaging concept promoted in US tennis is stepping into the ball, which helps the linear effort (linear kinetic energy) but destroys the circular effort (rotational kinetic energy).
Those organizations above, promoting the “similarities” of tennis with baseball and golf, favor the close and/or the semi-open (or semi-closed) stance.
They don’t realize that the open stance helps the linear and circular aspects at the same time! The best top players do it!
Open stance also puts the hand closer to the ball, helping control.
Read this 1992 book for free and decide for yourself what could be wrong.
With my best wishes, Oscar Wegner