The calendar Grand Slam stands as one of the rarest feats in professional tennis, with no male player completing it since Rod Laver in 1969, a reality that shapes overwhelming trader consensus around no winner in 2026. The compressed schedule across hard courts in Melbourne and New York, clay at Roland Garros, and grass at Wimbledon creates extreme physical demands, recovery challenges, and surface-specific adjustments that few athletes sustain at peak level. Carlos Alcaraz carries the lone non-zero implied probability thanks to his proven versatility and recent major titles, yet the market pricing accounts for the depth of competition from players like Jannik Sinner along with routine risks of injury or form dips over nine months. Any outcome other than none would require one competitor to avoid all setbacks while rivals falter across the full sequence of events.