query: SELECT 
     (wd:Q847 as ?item) 
     (SAMPLE(?a) as ?sample) 
     (COUNT(DISTINCT ?a) as ?ct)
     (wd:Q27020041 as ?type)
    ("0 b" as ?level)
    ("tennis season" as ?descr)
  WHERE
     { ?a wdt:P31 wd:Q27020041 ; wdt:P641 wd:Q847 }