The Snap (sometimes called the French Snap) is an old framer's shortcut. The trick is to saw one of your tenon shoulders, roll the stick twice, and saw the end cut down to the same depth as the shoulder cut you just made. Then strike the waste firmly with a heavy mallet or the poll of your axe and it will split the grain along the cheek of the tenon. This saves you from sawing half of the end cut and splitting one tenon cheek. Oh, Snap!