I picked up badminton in my late teens. I manage to grasp the basics and improve quickly. All I need is to improve my footwork and increase my stamina. Lately, I found out that I have to improve my shots too. I try to improve my overhead defensive shot but all I get is a shot that zips a few cm above the net and straight into my opponent's face/chest. Sounds nice but when it comes to a taller opponent, they won't hesitate to return the favour and smash it right back at my face. What did I do wrong? Is it the angle? The stroke? Thanks for the advice in advance.