I think there are a few things going on with why it is hard to learn and duplicate what you see from a high rated player just by watching.
The better your technique is, the more you can learn from just watching because you have done and felt enough of what you are seeing.
I actually remember, before I could loop, not being able to see the difference between a loop and a drive in what happens on the blade face from the rubber to the ball. The extended dwell time and that pull-ball effect, I remember not understanding what I was seeing and not seeing it properly.
Anyway, the biggest things that make it hard to sort out what is happening just from observation if your level isn't already decently high are:
1) The movement of the strokes are pretty darn complicated. The timing of the breaking of the elbow with the very small explosive movement from the hips and legs to pop into the ball all at the precise timing just before contact, is one example of the complication. If you look at Siva's first backhand in that video where the "multiball" switches from Siva feeding to him being fed, you can see he is trying to imitate a banana flip and it is pretty decent but it is much more circular than it should be and his followthrough is off to the side instead of forward. He did a pretty decent job of figuring some of what to do out but the movement is fairly inefficient in comparison to the stroke of a higher level player. However, his attempt to duplicate the technique of a forehand from observation has many more mechanical issues from a technical standing.
2) This, I think is even bigger: a person watching another person play, will usually tend to watch and pay attention to the flight and arc of the ball too. That makes it SOOOOO MUCH harder to actually see what the body movement actually was.
3) The last thing is that most of us are not really that highly skilled at watching someone else move and actually seeing what is happening. It is very hard to accurately see which joints move and which don't in a movement that happens so fast. To see what plane a particular joint moves a limb in is not easy either.
So a lower level player will invariably make a forehand swing that is much too large with a followthrough across the body and not high enough. This is because, in watching the FH, the stroke is so fast that it is sort of hard to see how much of a role the forearm and the timing of the wrist and hips play in the movement, and how much more stable the upper arm is and how much less movement happens from the shoulder than most people would realize unless their technique was already fairly decent.
This information is also why Brett Clarke's instructional videos are so particularly useful for helping people--especially adults--learn good technique.
Brett is particularly skilled at breaking down all the separate actions that happen in a stroke, and showing ways to help you learn how to isolate different joints.
That video where he uses the broom stick handle to show how to isolate the wrist and forearm and keep the upper arm from moving is actually total genius.
In the movie Topspin there is a scene where Ariel Hsing has a belt with a bungee strapped from her waist to her upper arm. When asked what it is she answers: "forehand fixing machine". For a high level forehand, you may not always keep your upper arm stable and only swing from the forearm and wrist. But a high level player will be able to isolate the movement from the forearm for the more compact strokes closer to the table. They will be able to do that whenever they choose.
Now, part of what I do in my work is actually movement analysis. Like, when I see someone replacing a movement from the acetabulum (main hip joint) with a movement of the spine to move the whole pelvic structure for walking, it tells me some good information about things that are going on with their hips and things that will help the person. Sometimes I see a person doing a movement with their arm that should come from the gleno-humeral joint but instead is coming from elevation of the scapula as a result of movement in the acromio-clavicular joint and the sterno-clavicular joint, and this will tell me about something going on with their shoulder and things that will help them.
Same kind of things with movements of the spine. Sometimes a movement that should happen in the thoracic spine happens in the cervical or lumbar spine instead.
Most people don't have training like that. I do.
And I can tell you for sure, that when my technique was worse, it was really hard for me to understand and break down the movements that go into making a good forehand or backhand stroke. In fact, despite my training, the complexity of the strokes, particularly the forehand stroke was not possible to sort out without decent training from someone who could see what I was doing wrong and how to correct it.
Using Siva's videos as an example one more time, he has been particularly good at learning how to get excellent spin on his serves. But, if you look at his body positioning, he is way more upright in those serves than the pros whose serves he feels he is duplicating. If you watch his forehand, his weight is too far back and he is too upright there too.
Those are hard things to change. Especially if you can't see that you are doing them.
So, none of this is to disrespect Siva. He is pretty darn good, especially for someone who is almost entirely self taught. But there are several things you can see that instantly tell you that he is a fast learner but that he taught himself a lot of things and that there are a few mechanical issues that cause his strokes to be more than a bit inefficient.
I have a few of those things in my strokes too. So, this is not a criticism. But I am using his videos as a useful example of how hard it would be to learn table tennis just by observing.
And you can forget about learning how to make brush contact from simply watching others.
Sent from Deep Space by Abacus