This is something I read months ago in "Cooks Illustrated" and wanted to see if all of you concur. The idea is was to keep the heat more even in the cooker. To do this, they used the charcoal chimney to get the initial coals going. At the same time they filled the fire pan with unlit coals. When the chimney was ready they dumped it onto the unburned coals in the fire pan. This burned more slowly than if they put the fresh coals on top of the lit ones (for obvious reasons) and ended up using a lot less charcoal. Essentially, it took longer for the coals to burn DOWN than it did for them to burn up. Seemed like a good idea to me so that's what I'm currently doing.