I acquired all of the Division I team data since 2002, and from that we can observe some fascinating trends and data relationships in the data. This is a multipart series exploring some of that data.
Finishing up with defensive shooting stats, we'll tackle Effective Field Goal Percentage Allowed (efg%). To review, this stat weighs 3-point shooting so that the value of the shot is considered in the percentage. The calculation for this stat is:
Both fgms and fgas include 3-pointers, but we add in 50% more for the 3fgms since that is how they are scored. The problem with this equation is that it is possible to get a result higher than 100%, but nevertheless, it still is more popular than overall field goal percentage in measuring a team's potency from shooting.
The graph shows the national average in grey, the average for NCAA Tournament teams in green, and UNC's average in blue.
From this we see that national eFG% has essentially hovered in the 49% range for the past 23 seasons, with a slight elevation in 2016. The standard deviation is 2.7 percentage points, so we see a wide variation among college basketball in this defensive stat.
Tournament teams demonstrated the same pattern as the national average, unlike with the eFG stat covered in Part 5. It appears, though, that tournament teams' opponents generally shoot 2.0 percentage points worse than the national average.
UNC's efg% history has followed the tournament average well until its last National Championship. Since then the program has lived between the national and tournament averages, a trait we haven rarely seen. The current team, however, appears to be exceeding the tournament by around 2 percentage points. That's only been seen with the 2012 and 2015 teams.
How useful is Effective Field Goal Percentage? It correlates with Winning Percentage more than most stats. On a scale of 0.0 to 1.0, it has a -0.627 correlation factor. Unlike its offensive counterpart, Effective Field Goal Percentage Allowed has a higher correlation factor than total field goal percentage. Therefore, this is an excellent stat to follow.
Next up: Percentage Loss of Ball Forced
Finishing up with defensive shooting stats, we'll tackle Effective Field Goal Percentage Allowed (efg%). To review, this stat weighs 3-point shooting so that the value of the shot is considered in the percentage. The calculation for this stat is:
Both fgms and fgas include 3-pointers, but we add in 50% more for the 3fgms since that is how they are scored. The problem with this equation is that it is possible to get a result higher than 100%, but nevertheless, it still is more popular than overall field goal percentage in measuring a team's potency from shooting.
The graph shows the national average in grey, the average for NCAA Tournament teams in green, and UNC's average in blue.
From this we see that national eFG% has essentially hovered in the 49% range for the past 23 seasons, with a slight elevation in 2016. The standard deviation is 2.7 percentage points, so we see a wide variation among college basketball in this defensive stat.
Tournament teams demonstrated the same pattern as the national average, unlike with the eFG stat covered in Part 5. It appears, though, that tournament teams' opponents generally shoot 2.0 percentage points worse than the national average.
UNC's efg% history has followed the tournament average well until its last National Championship. Since then the program has lived between the national and tournament averages, a trait we haven rarely seen. The current team, however, appears to be exceeding the tournament by around 2 percentage points. That's only been seen with the 2012 and 2015 teams.
How useful is Effective Field Goal Percentage? It correlates with Winning Percentage more than most stats. On a scale of 0.0 to 1.0, it has a -0.627 correlation factor. Unlike its offensive counterpart, Effective Field Goal Percentage Allowed has a higher correlation factor than total field goal percentage. Therefore, this is an excellent stat to follow.
Next up: Percentage Loss of Ball Forced
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