as he says, pullups put the most weight on the lats. but apparently, as i just found out, they arent necessarily better for working the lats. as i have recently heard, since the biceps assist the lats in chinups, that doesnt just mean that they are less beneficial to them because, they can work for a longer period of time. most people dont think of them this way. so maybe when working your back if you're going more for just strength, you can do pullups and for more endurance you can do chinups.