If I had to pick the most effective striking/grappling combination, it would be BJJ and Thai kickboxing. In karate, we use the ball of our foot or the instep for a roundhouse kick. I will never forget the first time someone did a Thai kick with their shin to the back of my leg!!! It almost dropped me. And, the guy held back. What a difference in effectiveness. The only downside to this type of kick is that you don't want to hit anything hard. It must be a soft target.
Email me if you want to see a video of a Thai boxer breaking his leg when he hits the shin of his opponent.
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