For flavorful hamburgers use a good grade of ground beef— ground sirloin, round or chuck. Avoid low-priced ground meat with high fat and gristle content. Besides lacking flavor, cheap ground beef "melts away" in the process of cooking.
For extra flavor mix ground onion with the meat, or season with hickory smoked salt.
Hamburger patties for broiling should be 1/2" to 3/4" thick. Use a "HI" or MEDIUM burner setting. For a smokier flavor lower grill hood while cooking.
Turn hamburgers only once. Second side will need only about half as much cooking time as the first side. Like cheeseburgers? Put a slice of cheddar cheese on each patty after it has been turned.
Hamburger patties at the outer edges of the cooking grill will need a little more cooking time. If you wish to accumulate cooked hamburger patties, use the potato rack. This will hold the hamburger patties far enough away from the flames to prevent over-cooking, but will keep them at serving temperature.