In professional tennis, achieving a Calendar Grand Slam by capturing all four majors in one year faces formidable obstacles, including surface-specific demands from hard courts to clay and grass plus the physical toll of a packed ATP schedule. No male player has accomplished the feat since the 1930s, and the modern era’s depth—with multiple top contenders vying for titles—reinforces the consensus that no athlete will sweep the Australian Open, French Open, Wimbledon, and US Open in 2026. While Carlos Alcaraz has posted strong recent results across surfaces, factors such as potential injuries, inconsistent form over nine months, and emerging rivals continue to limit realistic paths to a clean sweep, keeping the implied probability of success near zero.