What do birdie, eagle, and bogey mean in golf?

Par is the number of strokes an expert golfer is expected to need on a given hole, typically three, four, or five depending on length. Everything else is expressed relative to it. One stroke under par is a birdie, two under is an eagle, and three under is an albatross, sometimes called a double eagle in the United States. One over par is a bogey, two over a double bogey, three over a triple bogey. A hole in one on a par three is simultaneously an ace and a birdie, and on a par four it is an eagle.

The terminology is American and dates to around the turn of the twentieth century. Bird was slang for anything excellent, and the story generally credited places the first use at Atlantic City Country Club in 1899, where a player whose approach shot finished inches from the hole called it a bird of a shot. Eagle and albatross followed as escalations of the same bird theme. Bogey is older and British, originally meaning a score a competent player should achieve, essentially what par came to mean, before the two terms diverged and bogey shifted to mean one over.

Scoring formats build on this. Stroke play totals every shot across the round, and the score is reported relative to par for the course. Match play scores each hole separately, so a disastrous hole costs one hole rather than several strokes, which changes strategy considerably. Stableford scoring awards points by result, rewarding aggressive play since a bad hole simply scores zero. The handicap system exists to let players of different abilities compete, adjusting scores by an index calculated from recent rounds, which is why amateur competition can be meaningful across a wide range of skill.