of all the grilling I do, it has been a challenge to cook simple Boneless, Skinless chicken fillets on the grill. It's either over cooked and tough or under cooked and chewy.

I have no problem with skin-on rib split breasts. Mainly because they are bigger (and we like that!). Also, the skin provides more flavor and juice when cooked on the grill.

Well, I think I figured it out.

The fillets require more attention because they are thinner. You also want to use a marinade like Italian salad dressing which helps tenderize. Then a little Kosher salt, ground pepper or even a BBQ rub.

When your grill is ready, place the fillets directly on the fire for about 4 or 5 minutes a side. this will give them grill marks and sear them. After that, move them to the perimiter of the grill. Close the lid and cook for 20 minutes or so. Check after 15 minutes to see how they are doing... depending on cook temperature and size of the meat, the cook time may be more or less.

Hope this works for you!
Let me know.. JD