Top Tips for Cooking Burger Patties:

• Keep the patties cold/frozen until they hit the grill.  Unlike other meat that will cook up better if brought to room temperature before hitting the grill, you want those patties cold so they stay together and stay as juicy as possible. Put the patties on a tray or platter, covered, in the fridge while the grill heats up. This helps more of the flavor-carrying fat stay in the meat. Alternatively, place an ice cube in the middle of the patty as another way to minimize the patty from drying out.
   
• Use a hot grill. Keep the grill at a steady high heat (you can hold your hand 1 to 2 inches above grill level for 2 to 3 seconds). If using charcoal, you want ash-covered coals to produce even heat. With a gas grill, keep the lid down while cooking; with a charcoal grill, leave the lid off
   
• Controversial - Flip the patty once and only once! Constant turning will toughen and dry out the meat, and if you flip too soon, burgers will stick. Cook 1-2 minutes per side for rare, 2-3 minutes for medium-rare, 3-4 minutes for medium and 4-5 minutes for well-done.
   
• Don't press the burgers while cooking. This is an all too common mistake in burger grilling. It's also one that's heartbreaking to witness. When the cook takes a spatula and presses down on each burger, the juice just pours out onto the flame, taking all that moistness and flavor with it. Let your burgers hold onto their natural juiciness and just let them cook in peace! (One exception: if you're purposefully making "smash" burgers where you put the patty on a very hot griddle and smash it flatter in one fell swoop. This doesn't work well on a grill, for obvious reasons.)
   
• Let the patty REST! Resting allows burgers, like all meat, to finish cooking and allows their juices, which have collected on the surface during grilling, to redistribute throughout the patty for maximum juiciness. Since burgers are generally somewhat small (compared to giant roasts), just 10 minutes will do it.