Who was the first MLB player to achieve a 40-40 season (40 HR, 40 SB)?

José Canseco was the first MLB player to achieve a 40–40 season, combining at least 40 home runs with 40 stolen bases. He reached the milestone with the Oakland Athletics in 1988, hitting 42 home runs and stealing 40 bases.

Canseco secured the achievement late in the season. On September 23, 1988, he stole his 40th base, becoming the first member of baseball's 40–40 club. His power and speed made him one of the sport's defining stars of the late 1980s, and he unanimously won the American League Most Valuable Player Award that year.

The feat was especially notable because home-run hitters and base-stealers usually have different offensive profiles. Canseco's season demonstrated that one player could combine elite power with aggressive baserunning. His 40–40 season became a benchmark for later stars such as Barry Bonds, Alex Rodriguez, and Alfonso Soriano.

A common mistake is to credit one of those later players because they also joined the club. Bonds came closest to dramatically exceeding the benchmark, reaching 73 home runs and 13? No—his 2001 season included 73 home runs but only 13 stolen bases, so it was not a 40–40 year. Canseco remains the original member.