A PGA Tour leaderboard ranks the top golfers in an event based on how many strokes they have taken relative to par and also shows where they are on the course. Par is the pre-determined number of shots that an excellent golfer is expected to take to finish each hole.
During a golf tournament, there can be as many as 18 groups of golfers playing simultaneously. The leaderboard allows spectators at the course, who may only see the action at one hole, to nevertheless keep track of the progress of leaders in the tournament. Leaderboards are also shown on TV and are available online. Golfers who are in contention may use the leaderboard while planning their strategy, though some prefer to ignore the leaderboard and concentrate only on their own game.
Scores are compared to par because the leaders may all be at different points on the course, so it would be misleading to simply show who has taken the fewest strokes. Physical leaderboards on the course typically show the top ten golfers, while online leaderboards usually show everyone in the tournament.
An exception to the typical rankings occurs after the first two days of a PGA tournament, when the golfers with the poorest scores "miss the cut" and are eliminated from the tournament. In the standings from that point on, the golfers who remain in the tournament are always ranked ahead of those who missed the cut.