The iconic head atp ball. official ball of the atp world tour and the barclays atp world tour finals in london. find out more at head.com/tennis. the iconic head atp ball – preferred not only by novak djokovic for its liveliness and ability to reach maximum spin and control – now comes with additional and unrivalled durability. the flagship of head’s tournament balls with new encoretm technology and smartopiktm felt for greater visibility. official ball of the atp, many atp world tour tournaments and the barclays atp world tour finals in london.