Elbows for KIDS!!!
Let's pretend that I wanted to raise my son to become the most effective fighter. Most kids in the 80's and 90's started their formal training in striking disciplines like karate, TKD, or boxing because these were the most accessible/popular types of schools. So today you see this reflected in fighters in MMA where elbow strikes are not primary weapons. Interestingly, elbow strikes are one of the most effective and underrated knockout techniques. Most fighters are not used to being attacked by elbow strikes. Elbow strikes are also not very natural, because it wasn't the first strike you were taught as a kid. (unless you lived in Tailand)
I am training my son in elbow strikes first. Elbows are most effective in defensive techniques when opponents are rushing in, or unsuspecting opponents when you fly forward. An elbow strike will ALWAYS be your most powerful upper body strike. The problem is landing it to the head. If you train a kid on elbows first and have this become as natural as a jab or reverse punch, then you will give this kid a powerful technique that comes naturally.