The Major League standard for true speed and power was the attainment of thirty home runs and thirty stolen bases during any single season. In 1988, Jose Canseco set a new standard when he reached 40 / 40, but the combination of 30 / 30 is still considered a unique and very desirable blend of power and speed.
"If you get two-hundred hits a season, you're going to hit .333 and you'll still have four-hundred outs. I don't see why you have to run down to first base every time to make an out." - Bobby Bonds in Baseball's Greatest Quotations: An Illustrated Treasury of Baseball Quotations and Historical Lore (Paul Dickson, Collins Publishing, 09/02/2008, Page 66)
American League Players With 30 Home Runs and 30 Stolen Bases in a Season
National League Players With 30 Home Runs and 30 Stolen Bases in a Season
30 Home Runs and 30 Stolen Bases in a Season in Both Leagues
The National League might be older (started in 1876), but the American League (started in 1901) had the first 30 / 30 player in Major League history.
Did you know that Bobby Bonds was the first, and until 2006 when Alfonso Soriano tied him the only, Major League baseball player to hit at least thirty home runs and steal at least thirty bases once from each league?