A sarcastic form of the word "sports" in an ironic, yet, endearing way, mocking the genuine and sincere regard of Sports in general, as a concept.
With out blatantly "hating on" or "H8ting" "sports" -which would seem bitter or "angsty" coming from a repressed perspective. Using the word "Sportz" is a way for those who grew up not doing sports, nerds, geeks, art-kids, theater kids, dorks, and all other non-athletic persons to finally appreciate "sportz" in an indirect ironic way.
In the tradition of putting the letter "z" instead of "s" on the end of a word, which then makes it in the sarcastic form of the word ex. "guyz" or "gurlz" -- A misspelling in a pseudo-urban speak or spelling puts an ironic flair to the meaning.
"the humans are doing sportz today"
" the game is on" #sportz - if used on twitter
As in the portrayal of the use of the word "Sportz" in the Youtube video "We Like Sportz" by The Lonely Island produced by Andy Samberg