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."

Cubs general manager Dallas Green is shown here on the field at Wrigley, with a group of kids, on what shows on the scoreboard message board as "CUBS/INTERLAKE HONORS PROGRAM."

Exactly what is that? Here's the full image, which explains:

So, it was run by a suburban Chicago company to honor local grade school and high school students.

That's a noble thing, but what we're interested in here is: When was this photo taken?

First, this has to be from 1982. You can see the Chicago Sting clock below the scoreboard, next to the new message board which was installed that year after Tribune Company bought the team. In 1983, there were ads placed on either side of the message board and the Sting moved out of Wrigley Field.

We see a Cub wearing No. 8. Though he looks in playing shape, that's not a player. It's Tom Harmon, who was the Cubs bullpen coach in '82. Harmon never played in the big leagues and had been in the Phillies organization under Dallas Green, who brought him over, but just for that one year.

Anyway, now we turn our attention to the scoreboard, always the best clue for sleuthing out a photo of this type. The Cubs are hosting the Mets. There's ivy on the outfield wall, so this can't be the opening Cubs/Mets series in April. The matchups on the board are as follows:

NL: SAN FRANCISCO/ATLANTA, LOS ANGELES/CINCINNATI, SAN DIEGO/HOUSTON, NEW YORK/CUBS, PITTSBURGH/ST. LOUIS, MONTREAL/PHILADELPHIA

AL: BOSTON/BALTIMORE, MINNESOTA/CALIFORNIA, TEXAS/CLEVELAND, SOX/NEW YORK, DETROIT/KANSAS CITY, SEATTLE/OAKLAND

The following games are listed on the board as night games: PIT/STL, MON/PHI, BOS/BAL, MIN/CAL and DET/KC.

These matchups match those from Aug. 3 and 4, 1982.

At first, it doesn't appear to match because San Francisco and Atlanta, and the White Sox and Yankees, are both listed at baseball-reference as playing night games both those days.

However, a check of the Tribune archive shows the San Francisco/Atlanta game on Wednesday, Aug. 4 as starting at 5:05 p.m. Chicago time -- 6:05 in Atlanta, which would make it officially a night game. Similarly, the White Sox were at the Yankees for a doubleheader that was to start at 5:35 p.m. Chicago time -- 6:35 in New York.

But the scoreboard operators in those days often left the score line open for any game that started before 6 p.m. Chicago time, just in case the Cubs game ran long and they could start posting scores. Seriously.

So this board matches the games of Wednesday, Aug. 4, 1982. The scoreboard clock reads 12:37, so now we know precisely when this photo was taken more than 42 years ago.

The Cubs lost the game 7-4. It was one of Fergie Jenkins' rare bad outings that year, as he had a pretty good season at age 39. He allowed seven hits and five runs in four innings, including a home run to Mets pitcher Craig Swan. Future Hall of Famer Ryne Sandberg went 3-for-5 for the Cubs, including a double.

This game is famous for another reason. Look at the boxscore link and you'll see that Mets outfielder Joel Youngblood was pulled in the fourth inning. That's because he was traded to the Expos during the game. He caught a flight to Philadelphia, where the Expos were playing, and played the last three innings of that game, a 6-1 Montreal loss. He got hits in both games and to this day is the only player to play for two different teams in two cities on the same day.