It raises some interesting questions:
1) How many 5-game sweeps would we have had? My guess is none. It's very difficult for a team to lose 4 but imagine 5?
2) How many more games would Yogi Berra or Mickey Mantle have played in?
3) How many HRs would Mantle have hit? He hit 18 but my guess is that he would have hit 25 in "a best of 9" format.
Anyway, I am happy that it is "a best of 7" series. However, "a best of 9" would have probably allowed a few teams to come back from a 3-1 deficit, such as the 1969 Orioles.
Speaking of Judge Landis, he was quite a Commissioner: