OB - The abbreviation for the three saddest words in golf—out of bounds. You don't want to go there.

Obstructions - Golfers may move their balls away from or remove any artificial obstacles not part of the course such as torn and crushed hats and other discarded articles of clothing; chewed scorecards; ripped instruction books; halved golf balls; discarded golf clubs; demolished handcarts; and over turned and burning electric carts.

Observer - One who ensures that a golf match or round is played in accordance with the Rules of Golf.

On the Clock - Condition under which a group of slow-playing professionals is informed by tournament officials that their play will be timed to ensure it is in accordance with the rules and continued slow play will result in a penalty—a warning that usually draws a response of incredulity and disdain from the golfers. This slow play by the guys on TV is largely responsible for the five- and six-hour rounds that are so common on public golf courses today.

On the Screws - Description for a well-executed shot. In the good ol' days, when woods were made of wood, club makers fitted a plastic insert into the club face as a safeguard against premature wear. These inserts were fastened to the club with screws. When a golfer would hit a good shot, he would say, "I hit it on the screws."

On the Dance Floor - When the ball has stayed on the green.

Open - A tournament that is open to all players, amateur or professional, who can qualify. Big tournaments like the British and U.S. Opens are the goal of any talented golfer, but it is worth remembering that whereas in, say, tennis only 50 percent of the players in the men's singles final will lose, in golf more than 98 percent of the players in the final round of a tournament invariably fail to win.

Open Stance - At address the golfer stands with their front foot further from the ball line than their back foot. An open stance is used by a player when they want to fade or slice the ball.

Out of Bounds - A ball lies out of bounds and may not be played if the whole of its circumference is beyond the line marked by the stakes that form the golf course boundary. Many golfers feel, however, that a ball which appears to be out of bounds should, considering the curvature of the earth, be more properly regarded as in bounds since it lies a good 24,900 miles inside the out-of-bounds line.

Over Par - A score higher than the indicated par for a hole or round.

Overclubbing & Underclubbing - Using clubs that hit the ball over your target ("too much club") or short of it ("too little club") is a common mistake made by many players. You can overcome this error by understanding what each club can do, and meanwhile you can compensate by overlooking and undercounting, and, if caddies are present, by overtipping with an understanding.

Overlapping Grip - To hold the club such that the little finger of one hands is wrapped around the fore-finger of the other.