Al 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."
Here’s a photo where we have exactly one useful clue: The price of hot dogs at Wrigley Field.
Hot dogs were this price, 50 cents, for just two seasons, 1975 and 1976.
Other than that we don’t have much to go on here. There aren’t any readable scorecards, for example, which has helped in sleuthing other photos. I sent the photo to Mike Bojanowski. After I show it to you again, I’ll let you know his thoughts.