Only four players have ever hit 40 homers while stealing 40 bases in the same season. Remarkably, none of them are in the Hall of Fame.
Though Canseco became a pariah in later years, he left a lasting impression on the sport in 1988 when he clubbed a league-leading 42 homers and swiped 40 bags for the A's. His 40th homer came on September 18 while facing Bret Saberhagen of the Royals. He recorded his 40th stolen base five days later against the Brewers at County Stadium in Milwaukee. When Mickey Mantle learned of Canseco's feat, he commented: "Hell--If I'd known 40-40 was going to be a big deal, I'd have done it every year." Mantle collected 40 or more homers four times and finished in double digits for stolen bases in six consecutive seasons. His lifetime success rate as a base-stealer was 80 percent compared to Canseco's 69 percent. Canseco vastly overestimated his own running abilities. In his 2005 tell-all book, Juiced, he claimed to have run a 40-yard dash in 3.9 seconds. For the record, no athlete in any of the four major sports has ever recorded a time that fast.
The first National League member of the 40/40 club, Bonds accomplished the feat before he was linked to steroids, which makes 1996 the most remarkable season of his career in some respects. His 40th homer came on September 16 off of Padres right-hander Scott Sanders. His 40th steal came more than a week later in a game at Coors Field. Though he ended up winning seven MVP awards, he finished fifth in MVP voting during the '96 slate in spite of his league-leading 129 RBIs and lofty .461 on-base percentage. That same season, he became the fourth member of baseball's 300-300 club, joining his father (Bobby) along with Willie Mays and Andre Dawson.
A-Rod's big moment came on September 19, 1998, when he blasted a solo homer (his 40th of the season) off of aging Angels right-hander Jack McDowell. His 40th stolen base had come two weeks earlier in a game against the Orioles. An indication that the feat was little more than a bucket list item for A-Rod, he never stole more than 28 bases in a season during his remaining seventeen years in the majors. In fact, his 46 steals in '98 represented fourteen percent of his lifetime totals. On the other hand, the homers kept piling up for A-Rod over the years. He reached the 50 homer plateau three times and retired with 696 long balls--currently fourth on the all time list behind Aaron, Ruth and fellow steroid user Barry Bonds.
Perhaps the most unlikely member of the 40/40 club, Soriano had narrowly missed in 2002 with the Yankees, gathering 41 steals and 39 homers. He eventually broke through in 2006 while playing for the Washington Nationals. When he clubbed his 40th homer that year, he was 10 stolen bases short of inclusion. After swiping his 40th bag on September 17, he was somewhat surprised himself, commenting: "That's very amazing for me because there's a lot of players that can play this game. That's an amazing number." Over the next eight seasons, Soriano reached the 30 homer threshold twice, peaking at 34. His highest stolen base total in that same span was 19. An enduring claim to fame, he is currently the only steroid-free 40-40 man.