Record for multi-home run games, career.

[rurallib]

3. In Ruth's era baseball was about the only professional sport

so for those with athletic talent who wanted to make some money baseball was the major outlet. There was some pro football and more individual sports like golf, tennis and boxing.

In Bond's era the best athletes had many more choices from football to basketball and soccer. Don't know if that adds anything to the discussion. Of course segregation in the Ruth era eliminated a lot of great athletes and potential pitchers.

One argument I heard from an acquaintance who made it to AA ball was that the strike zones in the 90s and early 2000s were the size of a postage stamp forcing pitchers to throw a lot down the middle.