A.P. Hoops: The Three (point) Habits of Highly Effective Shooters

Gabe Pruitt, known as one of the NBA D-League's best shooters, needs a more advanced metric than FG% to measure his worth.
Dave Eggen/NBAE via Getty Images

Last week we discussed the key principles behind APBRmetrics and learned how to adjust for pace, allowing us to determine how efficiently players convert the opportunities they are given. If you need a refresher, AP Hoops 101 can be found here.

This week we'll start breaking down some of the specific statistics that comprise APBRmetrics -- a standard of measurement that, for our purposes, can pinpoint some great prospects that would otherwise be glossed over by the casual fan.

To introduce our next concept, let’s take a look at a very simple example. Let’s say the Iowa Energy's taking on the Los Angeles D-Fenders. Energy rookie phenom Jarrid Famous has his groove going in the post and makes six of his first 10 field goal attempts (FGA) from the block.

Using very simple math we determine that he would have a total of 12 points, and would have a stellar field goal percentage (FG%) of 60%. Now let’s pretend that his opponent, Brandon Costner, is feeling it from downtown and drills four 3-pointers out of his first 10 shots, totaling 12 points and giving him a FG% of 40%.

Now we’re left with a tough predicament. Both players have 12 points, and looking at their FG% would tell you that Jarrid Famous is a “better shooter” than Brandon Costner. But clearly there’s more to this story: 3-pointers are more difficult to make than 2-pointers, but come with the added reward an extra point.

So now we ask ourselves...

After all, both players in our example took 10 shots to score 12 points.

As you may expect, the glorious land of APBRmetrics has an answer: A simple solution called effective field goal percentage (eFG%).

This statistic is one of the cornerstones of statistical guru Dean Oliver’s “Four Factors of Basketball Success” (which we will address in more detail in future articles) and provides a much more accurate assessment of shooting efficiency. eFG% corrects the “3-point problem” by counting each converted 3-pointer as one-and-one-half made field goals to reflect the 3:2 ratio between a three-pointer and two-pointer.

So let’s use our previous example to make sense of this mathematical jargon.

When you’re done having your Algebra I flashback or suffering from a quick bout of mathematical PTSD, you will realize that eFG% successfully equated the shooting efficiency performances of Famous and Costner to reflect the fact that each player scored 12 points with 10 shots.

Now we’ll roll up our sleeves and take a look at the top performers in the NBA D-League this season with regards to FG% and eFG% for players who have taken at least 30 shots. When examining the data below, note how 3-point shooters are noticeably absent from the FG% list but are featured prominently in the eFG%. Furthermore, you will notice that players who shoot many 3-pointers typically have the biggest discrepancy between FG% and eFG%. And pay special attention to the fact that only one player in the top five in field goal percentage (Rio Grande Valley forward Marshall Brown) appears in the top five in eFG%.

Note: All data was provided by NBA StatsCube.