"I don't know why there would be [an era] for doubles," said Bill Nowlin, the vice president for the Society for American Baseball Research (SABR). "I could see it for home runs. You have all kinds of explanations you can look at for statistics — when the race barrier dropped, which is also the same time teams started playing night games. A lot of things started changing in the middle-40s, but I don't know how any of that would have changes hitting doubles. … There are things that are just outliers, things that just happen. It's just that nobody has gotten to 67. Probably someone will some day."