In how many different teams have all those who have played as a defenceman been?
SELECT DISTINCT COUNT(?uri) WHERE { ?x <http://dbpedia.org/property/position> <http://dbpedia.org/resource/Defenceman> . ?x <http://dbpedia.org/property/playedFor> ?uri  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/SportsTeam>}
Defenceman