We need to examine the correct reasons for the loss. Once that is identified, we need the player to agree to it and then to deal with it. And very often the player will need to be shown how and a game plan developed.
I have seen so many players lose for non technical reasons. And yet they are only given a technical evaluation. The solution isn't there. And so the problem is further compounded, deepened.
With no viable solution, the player continue to lose confidence and eventually they drop out.
You do not build a player who is suffering from a loss of confidence by telling them they are stupid or is without talent; their mind is already disassembling. More pressure and no solution will only hasten their downfall. By offering them shortcuts you are only ensuring they will never recover. You are only confirming their fears that they are not good enough.
The fact is different players will bloom at different times. And you cannot compare apples with oranges. Some have more technical support and at an earlier age than others. Also their giftings are not identical.
Mind coaching is a slower process but it works simply because you are looking at the underlying causes. When the real cause is examined and resolved, then the technical will bite. The knowledge can be used.