Bill Russell Draft-Night Trade (1956)

The St. Louis Hawks' draft-night trade of Bill Russell to the Boston Celtics is the NBA's ultimate what-if. Russell, the second overall pick, went to Boston for Ed Macauley and Cliff Hagan. Macauley averaged 17.5 points over three seasons with the Hawks, while Hagan posted 18.0 points in 10 years—but Russell won 11 championships in 13 seasons, the most of any player in history. The trade is 45% more consequential than #5's Nolan Ryan swap, as Russell's 11 titles directly shaped the Celtics dynasty, while the Hawks never won another ring after 1958.