It doesn’t happen very often.
If you think about it – we’re talking an average of about 160 games per team since – let’s say 1900. For just one team like the Braves, or Dodgers, or Red Sox we’re talking nearly 18,000 games. Then the number of MLB teams has grown from 16 to 30. If we take an average of maybe 20 teams over 109 year span, we’re talking close to 400,000 games (or so). Okay, let’s average it out to 500,000 Major League Games having been played. (Yea, I know the official start of MLB was in 1869, but I’m allowing for modern play.
Now, divide half a million by 18. We’re talking a perfect game every 28,000 MLB games or so. That’s how long we may need to wait before we see another one because the law of caught up with Mark Buehrie. In fact, no member of the Chicago White Sox had pitched one since 1922 when Charles Robertson did it on April 30.
The last Perfect Game was pitched by Dereck Lowe on April 27, 2002.
Buehrie’s Perfect 9th Inning MLB video.