Codermetrics

The Purpose of Metrics

There are three reasons to gather and use metrics. Of course there may be more reasons too, but in this book I will focus on three.

The first purpose of metrics is simply to help you track and understand what has happened. The subjective observation of situations, while sometimes insightful, is often colored by personal biases and experiences. It is dominated by the details you notice and are attuned to, and it misses the things you don’t see or recognize.

For example, if you attend a baseball game, and at the end someone asks what you remember, you will describe some of the plays that stood out. Maybe a big hit, or an exciting defensive play. But there will be a lot of details you forget, even though they just happened in the last few hours. Some you just won’t remember, maybe some you didn’t notice, maybe others you didn’t even see because you were at the hot dog stand. Also, how much you remember and what you describe will depend on how familiar you are with baseball, how many games you’ve seen before, and how much you know about different aspects of the game.

Alternatively, if you look at a box score of key statistics from a game, you can tell a lot about what happened in the game, whether or not you attended. And if you look at a complete statistical breakdown, with full offensive and defensive statistics and details on all scoring, then provided that you know what the statistics mean you can tell a great deal about the game, the players’ contributions, ...