query: SELECT ?item ?itemLabel ?event ?eventLabel (GROUP_CONCAT(DISTINCT ?sportL; separator=', ') AS ?sportLabels) WITH {
    SELECT ?item ?p1 ?p2 WHERE {  
      ?item p:P1344 ?p1; p:P1344 ?p2 .
      FILTER(?p1 != ?p2) .
    }
  } AS %subquery WHERE {
    INCLUDE %subquery .
    ?p1 ps:P1344 ?event .
    ?p2 ps:P1344 ?event .
    OPTIONAL { ?item wdt:P641/rdfs:label ?sportL . FILTER(LANG(?sportL) = 'en') }
    SERVICE wikibase:label { bd:serviceParam wikibase:language 'en' }
  } GROUP BY ?item ?itemLabel ?event ?eventLabel