Don't use just any old knife on your roasts. The best one has these traits:

Length and flexibility. To negotiate turns around the bone, the blade needs to be thin and long — at least nine inches.

A Granton edge. This means the knife has a series of hollow ovals ground into both sides of the blade. The ovals prevent the meat from sticking to the blade during carving, and they allow for smooth, even slices.

Comfort. The knife should feel natural in your hand. It shouldn't be too heavy. You want to control the carving knife, not the other way around.

The knife pictured above is the 10-inch Wusthof Gourmet Roast Beef Slicer ($60, www.cooking.com. It’s light and long and has a Granton edge.