I played David Howard the week before he won the U.S. Open in New London CT. David never used a closed bridge at that point in his career. He finished second in that particular tournament, The Eastern States Nine-ball championships. I have a rule of thumb, on open and closed bridges. If i'm asking a lot of the cue-ball, I use a closed bridge. If I'm not asking a lot of the cue-ball, I use an open bridge. Both bridges should be solid. There the foundation of your shot.