On this date in 1991, Rickey Henderson became the all-time stolen base leader, notching his 939th swipe to pass Lou Brock. Exactly one year later, on May 1, 1992, Rickey Henderson stole his 1000th stolen base. He remains the only player to reach four-digit territory, and will probably remain there forever by himself. He played 11 seasons after No. 1,000, adding 406 more bases to his all-time total. 

To give this more perspective, only one player in baseball has as many career stolen bases as Rickey swiped after that millennial swipe: That would be Juan Pierre, who at age 31 is an offensive player so limited that he has only been penciled into the starting lineup three times this season. He has 424 career stolen bases and it doesn't seem likely he'll reach 500, much less challenge anyone for their spot among history's greatest basepath thieves.

Truth is, the career stolen base list has barely changed since Henderson stole No. 939. The top 14 hasn't been touched since April 21, 1996, when Vince Coleman stole his 745th base to move to sixth on the all-time list, just behind Tim Raines, who reached fifth on September 4, 1993. (Kenny Lofton moved past Otis Nixon for 15th in 2007.)

But while the top of the stolen base list has remained untouched for more than a decade it doesn't come close to the toughest category for a modern player to infiltrate — triples.

Roberto Clemente, 27th on the all-time list, is the most recent player in the top 50 for triples, and he died in 1972.  So while Rickey Henderson is holder of the second-most impregnable offensive record in all of baseball, Sam Crawford can claim a stronger grip since he has held the triples record with 309 three-baggers since 1913. Thanks to modern defense and park construction, it's safe to assume that he'll keep it forever.

Still, it's hard to imagine that Rickey Henderson's record, which turns 18 years old today, is any less untouchable. (Sorry, Juan.)

You can read more of Alex Remington at Chop-n-Change, an Atlanta Braves blog.