I've always aimed 6-8" up from the brisket, even with the back of the leg on broadside shots. Anything with an angle changes the aiming point of course. Liver shots are deadly, especially when combined with a lung hit. The buck I killed in 2008 was an old, big bodied warrior. I shot him quartered away at 32 yards, eye level. The Rage 2-blade cut his liver in half, and cut a 2-3" section off the top of both lungs. He died in a matter of seconds, making it less than 40 yards from the shot. So I see what Perez is saying, just not something I'd advocate teaching new archers. Take the shot that gets you the heart/lungs and know that a miss in the back of the lungs/liver will kill 'em dead TOO!