Based on these results, it appears that the function f(x) is selective for racket sports, as it has high values for squash and table tennis in addition to the previously tested tennis and badminton. All other sports and concepts tested so far have shown low values. 

[DESCRIPTION]: The function f(x) is selective for racket sports, assigning high values to words associated with racket sports such as tennis, badminton, squash, and table tennis.