Frisian handball ( Dutch : kaatsen , Frisian : Keatsen ) is a traditional Frisian sport , related to American handball and fives , that is most commonly practiced by people from the northern province of FryslÃ cents n , or Friesland . Friesian handball ( Frisian Keatsen , ) is a traditional Friesian sport , related to American handball and fives , that is most commonly practiced by people from the northern province of FryslÃ cents n\/Friesland .