Good Shots are above the 66th percentile, Bad Shots are below the 33rd.
ShotQuality calculates an expected field goal percentage for every shot based on location data and individual player skill levels.
From this expected percentage we are able to calculate the expected value (SQpoints) of each shot by multiplying the value of the points attempted. By measuring every single shot in the entire college basketball season in this way, we can determine the thresholds that define the statistical thirds of the entire dataset. We grade shots Good or Bad, with the rest being Average, in the following way:
Good Possessions
If a player's possession is above the 66th percentile (of all college basketball) on a play then they get credit for a good possession.
The 66th percentile is 1.24 SQpoints for this past season.
So, if a player shot a three pointer above 41% then that'd constitute as a good possession.
Because the SQpoints would be greater than 1.24 (3 x 0.42 = 1.26).
Or, if a player took a 2 point layup that had above a 62 % conversion (2 = 0.63 = 1.26) then that would also count as a good possession.
Because the SQpoints would be greater than 1.24 in both instances.
Bad Possessions
If a player has possession that is below the 33rd percentile (of all college basketball) then they're credited with a bad possession.
The 33rd percentile is 0.77 SQpoints for this past season.
So, if a player shot a contested three pointer less than 26% then that'd constitute as a bad possession (3 x 0.25 = 0.75).
Or, if a player took a contested 2 point shot that had below a 39% conversion (2 x 0.38 = 0.76) then that would also count as a bad possession.
Because the SQpoints would be less than 0.77 in both instances.