The software application Golfmetrics was created to capture and store golfer shot data and to quantify differences in shot patterns between players of different skill levels. Across golfers it is shown, somewhat surprisingly, that longer hitters tend to be straighter than shorter hitters. Individual golfers can be measured relative to a benchmark to assess relative accuracy and to suggest whether to focus on increasing distance or decreasing directional errors. For amateur golfers, distance errors on short game and sand shots are shown to be about three times larger than direction errors. Shot value is a quantitative measure of the quality of each shot in comparison to a scratch golfer. Shot value analysis is a useful way to measure consistency, assess a golfer's relative strengths and weaknesses, and to indicate where practice and improvement are most needed. For amateur golfers a significant contributor to high scores is inconsistency, i.e., a relatively small number of awful shots. This research also quantifies the contributions of each part of the golf game (putting, short game, sand game or long game) to overall scores for golfers of different abilities. The long game is found to be the biggest factor in the difference in scores between pros and amateurs and between low- and high-handicap amateurs.