I tell the athletes I coach all the time that it is perfectly ok to fail. In fact, I go as far to tell them that they have to fail if they truly want to get better. Failing is an enormous part of growth. Successful people in sports, business, and elsewhere often have stories of big failures or a series of failures before they finally break through. Too often in Junior Tennis we are focused so much on the product of winning that we can sometimes lose sight of how valuable a loss can be.
In training I tell players all the time to take risks. Hit shots a little harder or a little closer to the line instead of worrying so much about never missing and being perfect all the time. It is a whole lot better to test the limits of your skills and make mistakes in training than in an actual match. When a player constantly pushes themselves to the point of failure they test the limits of their current skills, at the same time improve by pushing themselves past the edge of their abilities and then bringing themselves back.
Losing in matches may be the biggest catalyst to improvement a player can experience. Too often players actually hold back in competition as a means to protect themselves. They actually do not give it 100% rationalizing that if they lose without really giving it their all it somehow will protect their self-esteem and confidence. Players have to come to terms with the fact that they are going to lose and that is not a bad thing. Certainly, it hurts when you lose a match when you give it your all. It hurts anytime in life when you give it your all at something and fail. However, it is what you do with the failure that becomes the catalyst for change. Players who blow off losses never learn the valuable lessons by looking at the loss. Players who use the loss as a means to improve always get better. Players who figure out the reasons why they lost whether it be fitness, shot selection, or stroke production now know exactly what to laser focus on in their training. If they frame the loss as a valuable insight into where they are weak, practice that weakness relentlessly, and use the whole process as motivation to get better, they get better fast!
Junior tennis is developmental, not professional. At the professional ranks of the ATP and WTA tour winning and losing matter a lot and it should but you have to remember these professionals have spent their entire life developing their games. Even then professional players still learn from their losses. Your junior player is not a professional, they are in the developmental process, and losing is a part of that process.
I tell players all the time they have to be willing to give it their all in their training and risk it all in competition. Failure is a part of the process, it hurts to fail yes, but in the end it is one of the biggest catalyst to improvement in the game.
Even if you child has no aspirations of playing on the professional tour losses are an important part of the improvement process. Even more important think about the life lesson your child can learn from this. They learn that failure is a part of growth. Now fast forward in life to when your child has a new idea, fails a few times with it, uses those failures to improve, and then breaks through and develops the next iphone, hybrid car, cures cancer, or something even greater. Being a failure is definitely a part of the process to becoming successful.