@theline_show: 'The first step of progress is awareness' Search 'The Line Jason Stacy' on YouTube to watch the full conversation. Jason Stacy, coach to the world’s No. 1 tennis player Aryna Sabalenka (@Aryna Sabalenka), explains how a shift in mindset led to Grand Slam victories. #ArynaSabalenka #sabalenka #tennis #Wimbledon