One of the rarest occurrences in baseball happened Saturday in Seattle—a perfect game. Phillip Humber of the Chicago White Sox retired 27 consecutive Seattle Mariners in a 4-0 win.

That’s the 21st perfect game out of hundreds of thousands of major league baseball games.  We’ve had a flurry of perfect games in recent years. Mark Buehrle threw a perfect game for the White Sox in 2009.  Dallas Braden of Oakland and Roy Halladay of the Phillies recorded perfect games in 2010. Prior to Buehrle’s effort, baseball hadn’t seen a perfect game since Randy Johnson threw a perfect game for Arizona in 2004.

It’s not uncommon for three or four years to pass between perfect games. Sometimes decades separate these gems. White Sox righty Charlie Robertson threw a perfect game on on April 30, 1922 at Navin Field in Detroit. (later known as Tiger Stadium) The next perfect game was Game 5 of the 1956 World Series when Don Larson set down 27 consecutive Brooklyn Dodgers. That was a span of over 34 years.

The span between regular season perfect games exceeded 42 years. The next regular season perfect game to follow Robertson’s effort came from Jim Bunning and the Phillies on June 21, 1964.  That may also be last really positive memory of the ’64 season for Phillies fans.

Everyone in the ballpark in Seattle will remember that as long as they live. I know from first hand experience.. I was in attendance for Mark Buehrle’s perfect game in 2009. More on that experience soon.