Imagine being told your serve isn't good enough in a Grand Slam final, only to bounce back by naming the player you believe has the greatest serve in tennis history. That's exactly what Jannik Sinner did, and it's a testament to his resilience and deep understanding of the game. But here's where it gets controversial: Sinner didn't pick one of the 'Big Three' or even his rival Carlos Alcaraz. Instead, he chose the towering John Isner, a player whose serve has left countless opponents in awe—and Sinner himself isn't immune to its power. Sinner, a four-time Grand Slam champion with 21 ATP titles to his name, knows a thing or two about facing big servers on the ATP Tour. Yet, he was recently reminded of the importance of a dominant serve when he fell to Alcaraz in the US Open final, with critics pointing out that his serve wasn't up to par. Fast forward to the Six Kings Slam exhibition in Riyadh, Saudi Arabia, where Sinner is defending his title after last year's historic $6 million win—the largest prize money in tennis history. Amidst his on-court battles, Sinner sat down with Wivo Productions to build his 'perfect player,' and the results are fascinating. While he included Alcaraz for his forehand and tennis IQ, and the 'Big Three' in various categories, it was Isner's serve that stood out as the ultimate weapon. And this is the part most people miss: Sinner didn't just admire Isner's serve from afar—he faced it three times in his career, winning two of those encounters. Even on quicker surfaces where Isner's serve is most lethal, Sinner managed to break him five times during their 2021 Davis Cup Finals match, winning over half the points against his serve. Isner, standing at 6’10” (2.08m), retired in 2023 after hitting a staggering 14,470 aces and reaching a career-high ranking of world number eight. His serve wasn't just powerful; it was a game-changer. Sinner's choice sparks an intriguing debate: Is Isner's serve truly the best of all time, or are there other contenders? What do you think? Is Sinner's pick a nod to Isner's dominance, or is there another player whose serve deserves the crown? Let’s discuss in the comments! Sinner's next challenge at the Six Kings Slam is none other than Novak Djokovic, the 24-time Grand Slam champion. This rematch comes after Sinner's commanding win at Wimbledon, setting the stage for another thrilling showdown. Whether you agree with Sinner's choice or not, one thing is clear: the serve remains one of tennis's most decisive weapons, and mastering it—or facing it—can make all the difference.