During the 20th century, 198 no-hitters were pitched in 152,364 regular-season games, meaning there was 1 every 770 games. (Adding in post-season play, we have 199 no-hitters in 153,333 games [1 post-season no-hitter in 969 post-season games during the 20th century (564 World Series, 200 A.L. playoff games, 205 N. L. playoff games)]; counting post-season games, the frequency of a no-hitter is still 1 every 771 games.) Of course, in every game there is a chance for two no-hitters, one by either team. So, for a particular team, we have to cut that probability in half, 1 every 1,540 games, about the equivalent of every nine-and-a-half seasons.
Major League No-Hitters of the 20th Century By Decade
(Games Played/Complete No-hitters of at Least Nine Innings)
1901-10
American League 5,998/12 1 every 500
National League 6,020/ 9 1 every 668
Total 12,018/21 1 every 572
1911-1920
American League 6,031/16 1 every 377
National League 6,035/ 7 1 every 862
Total 12,066/23 1 every 525
1921-30
American League 6,164/ 4 1 every 1,541
National League 6,159/ 4 1 every 1,540
Total 12,323/ 8 1 every 1,540
1931-1940
American League 6,154/ 6 1 every 1,026
National League 6,159/ 4 1 every 1,540
Total 12,313/10 1 every 1,231
1941-50
American League 6,181/ 5 1 every 1,236
National League 6,198/ 7 1 every 885
Total 12,379/12 1 every 1,032
1951-1960
American League 6,183/10 1 every 618
National League 6,189/ 9 1 every 688
Total 12,372/19 1 every 651
1961-70
American League 8,426/14 1 every 602
National League 8,243/20 1 every 412
Total 16,669/34 1 every 490
1971-1980
American League 10,292/13 1 every 792
National League 9,675/15 1 every 645
Total 19,967/28 1 every 713
1981-90
American League 10,951/12 1 every 913
National League 9,386/ 7 1 every 1,341
Total 20,337/19 1 every 1,070
1991-2000
American League 10,874/12 1 every 906
National League 11,046/12 1 every 920
Total 21,920/24 1 every 913
Totals: 1901-2000
American League 77,254/104 1 every 743
National League 75,110/ 94 1 every 799
Total 152,364/198 1 every 770
No-hitters 1973-2000 (era of designated hitter rule):
American League 37 in 30,222 (1 per 816 games)
National League 28 in 28,187 (1 per 1,007 games)
Counting post-season games, the total is 199 no-hitters in 153,333 games during the 20th century-1 every 771 games.
Courtesy of:
Major League No-Hitters of the 20th Century
By Stew Thornley
Halsey Hall SABR Chapter Meeting, October 13, 2001
I disagree that the fielder who makes an outstanding play is rarely mentioned when no-hitters or perfect games are thrown. The fact that they occur on average fewer than three times each season makes it extraordinary.