What does per stand for in basketball?

The player efficiency rating (PER) is a rating of a player's per-minute productivity.

To generate PER, I created formulas -- outlined in tortuous detail in my book "Pro Basketball Forecast" -- that return a value for each of a player's accomplishments. That includes positive accomplishments such as field goals, free throws, 3-pointers, assists, rebounds, blocks and steals, and negative ones such as missed shots, turnovers and personal fouls.