In golf, an average is defined as the number of strokes it would take a scratch golfer to complete the hole. The average for each hole on a regulation golf course is based on par, which is the number of strokes it should take a skilled golfer to complete the hole. For instance, a par-3 hole should be completed in three strokes, while a par-5 hole should be completed in five strokes.
The USGA (United States Golf Association) has calculated that the average score for all golfers is 97. This means that, on average, it takes 97 strokes to complete 18 holes of regulation golf. Therefore, the average number of holes played in a round of golf is 18 ÷ 97 = 0.1868 or about one-fifth of a hole.
It's important to keep in mind that this figure is just an average and doesn't necessarily reflect how most people play golf. For example, many recreational golfers will never reach their average because they often take more than 97 strokes to finish 18 holes. On the other hand, some professional golfers may regularly shoot scores below 97 and thus play more than one full round per game (e.g., Tiger Woods averaged 71strokes per round during his PGA Tour career).