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Range method

As explained in Statistics Slam Dunk

The range method standardizes a numeric variable by dividing its values by the difference between the maximum and minimum values.

The range method standardizes a numeric variable by dividing each value by the difference between its maximum and minimum values. It places observations on a common scale and is especially useful when comparing variables measured in very different units. section 19.4.4 section 20.8

For NBA scoring, calculate the denominator within each season so players are compared with the scoring environment of their own year. Group the data by Year, create r_ppg with PPG divided by max(PPG) minus min(PPG), and round the result. section 19.4.4

Standardizing points per game by season

The R workflow creates r_ppg for every player, then groups the results by Year and selects the maximum standardized value. The leading scorer in each season receives 1.1 in the shown output, while lower values indicate smaller points-per-game values relative to that season's range. section 19.4.4

dat2 %>%
 group_by(Year) %>%
 mutate(r_ppg = round((PPG) / (max(PPG) - min(PPG)), digits = 1)) -> dat7a

head(dat7a, n = 3)
## # A tibble: 3 × 5
## # Groups:   Year [1]
##   Year  Player         PPG Year_Player       r_ppg
##   <fct> <chr>        <dbl> <chr>             <dbl>
## 1 1950  Al Guokas      3.8 1950 Al Guokas      0.2
## 2 1950  Alex Groza    23.4 1950 Alex Groza     0.9
## 3 1950  Alex Hannum*   7.5 1950 Alex Hannum*   0.3

tail(dat7a, n = 3)
## # A tibble: 3 × 5
## # Groups:   Year [1]
##   Year  Player           PPG Year_Player         r_ppg
##   <fct> <chr>          <dbl> <chr>               <dbl>
## 1 1999  Walt Williams    9.3 1999 Walt Williams    0.4
## 2 1999  Walter McCarty   5.7 1999 Walter McCarty   0.2
## 3 1999  Will Perdue      2.4 1999 Will Perdue      0.1

Inspect the complete R transformation and its first and last records, including the calculated r_ppg values. section 19.4.4

How Statistics Slam Dunk covers it

How deep it goes
Defines the formula and demonstrates grouped R calculations, but does not develop mathematical internals or limitations.
Examples
Demonstrates seasonal NBA points-per-game values, including standardized scoring leaders such as George Mikan and Neil Johnston.
What it assumes
Assumes a numeric variable with identifiable maximum and minimum values and introduces standardization through NBA scoring comparisons.
What you can do after
Apply it via R to standardize grouped numeric variables and identify the highest standardized observation in each group.
How it connects
Connects data standardization with points per game, maximum, minimum, z-score, standard deviation, and centering methods.

Related concepts

This explainer was generated by Manning's knowledge graph from the text of Statistics Slam Dunk. The section links point to the parts of the book it draws on.