A metric used in NBA basketball that is similar to Field Goal Percentage, but adds an additional parameter. This parameter adjusts for the fact that 3-point field goals are worth 50 percent more than 2-point field goals.
Basic basketball statistics have long been unfair to players who shoot a lot of 3-pointers. Players who take and make a large number of 3-point shots often don't have a very impressive field goal percentage, but that doesn't tell the whole story in terms of the points that player produces.
Take, for example, a player like Hall of Fame center Bob Lanier. He generally did all his scoring around the basket. He had a career field goal percentage of 51.4, but since he did all his scoring in the lane, his effective field goal percentage was also 51.4.
Now by contrast, let's look at a player like Hall of Fame guard Reggie Miller, who made 2560 3-pointers during his career. His career field goal percentage was 47.1, but because of all the 3-pointers he made, his effective field goal percentage was all the way up to 54.4.