Preheat grill to 450 degrees surface temperature. That is a little above medium for me but is medium-high on most grills. Use the entire grill surface. Clean and oil well.
While the grill is preheating, trim the thighs of any trim-able fat and extra skin and allow to rest at room temperature until grill is ready. No longer than 30 minutes but this will help get to the correct internal temperature later.
Just before placing on the grill give all sides a sprinkle of salt and pepper to your taste. I use my 7:2:2 which is salt, pepper and garlic powder. But season to your taste.
Using only half the grill surface, place on grill with skin side UP. Grill for 5-6 minute then flip onto the other side of the grill. Grill for about 4 minutes with the skin down and then flip. Continue to alternate sides of the grill to help keep the flair up down and continue the "uneven" grilling.
Grill to 180-185 internal temperature. Right at 25 minutes for me but this will vary some with your exact grill surface temperature, the temperature of the thighs and thickness.
Allow to rest for 5 minutes before serving.
As always, cook to the final internal temperature. Do not cook by time alone. I used my 7:2:2 seasoning but season to your taste. Just some Kosher salt and pepper would do.
Do not try this with partly frozen chicken; you will never get to the correct internal temperature. A little rest at room temp before cooking helps (30 minutes max).
Use 180-185 as my final internal temperature. This is where thighs are done. They are safe at 165 but are still tough.
Grill on a medium grill not super hot. TRIM THE FAT. Use the uneven grilling technique discussed.