One (obvious) reason why there are more perfect games

Contrarian reader Andrew Douglas makes the obvious point that there are a lot more Major League Baseball games nowadays than there were in the first six decades of the 20th Century, and they play a slightly longer season. That can account for some—but probably not all—of the recent flurry of these exceptionally rare events that I remarked on yesterday. From 1901 through 1960, with minor variations, 16 teams played 154 games per season, for a total of 1,232 games per year (16 x 154 ÷ 2). In 1961, the season was lengthened to 162 games, an increase of about five percent. Baseball...