Lately I've been thinking quite a bit about something I heard Otto Heino say in a video. As it showed him centering a huge piece of clay, about 50 pounds, he commented that he always makes sure he centers his piece of clay all the way down to the wheelhead. At first that struck me as an obvious point. "Of course you center your clay all the way down to the wheelhead. What other kind of centering is there?" And then I realized there's at least one other kind of centering. Potters have been using it successfully for many years when they throw off the hump. When you throw off the hump, you only have to center more precisely the small lump that you're working on at the top of the hump. If you've thrown off the hump, you know that the very top of your piece of clay can be perfectly motionless even though the clay at the bottom of the hump is off center. When I thought about my own centering, especially of large pieces of clay, it made me realize that my centering was more like throwing off the hump. When I centered a large piece of clay, the top would be motionless so it looked like the whole lump of clay was centered but it was still off center at the very bottom, right at the wheelhead. As soon as I opened the hole my cylinder went off center because the hole went all the way down to the off center clay at the bottom. This made it more difficult to pull the walls, and almost impossible to shape the piece in the way I wanted. I don't know if some of you have noticed this or not, but if you find your clay going off center when you open the hole or if it feels wobbly when you start pulling up the walls, maybe it wasn't properly centered all the way down to the wheelhead. I think that's what Otto Heino was getting at, and it's helped to clear up quite a few problems I was having, especially working with larger pieces of clay.