Sports Novak Djokovic’s magic number? Five. That’s how many wins he needs for calendar-year Grand Slam. September 2, 2021 Alex Coffey Comments Off on Novak Djokovic’s magic number? Five. That’s how many wins he needs for calendar-year Grand Slam. The No. 1 men's tennis player defeats Tallon Griekspoor 6-2, 6-3, 6-2, says he has found his rhythm in his serve. That's bad news for Kei Nishikori.