Cubs historical sleuthing: Fergie Jenkins, 1970s edition

Photo by Focus on Sport/Getty ImagesAl Yellon created Bleed Cubbie Blue and has been its managing editor since 2005. He's also written three books about the Cubs, the latest is "Chicago Cubs Firsts."

You might not think there are enough clues here, but dear reader, you know how long I’ve been at this, and I am here to tell you there are enough clues in this photo of Fergie Jenkins to at least narrow it down to xxx.

First, here’s the entire photo, which I cropped above.

Photo by Focus on Sport/Getty ImagesGetty Images says the photo is “circa 1970,” which sort of helps but could make it just about any time.

There is only one thing we know absolutely for certain about this photo: It had to be…