From SABR member Tom Ruane at Retrosheet on May 5, 2014:
This is an article about the age of starting lineups. Although I suspect this topic has been covered before by other baseball researchers (and if you send me links to their work I will add them here), I suspect that few if any of them have beat the subject as thoroughly to death as I am about to do.
We’ll start by simply looking at the average age of the nine starters (or ten, in the DH-era AL) and then move on from there.
When I started this, I was hoping that the youngest starting lineup in the last 100 years would be something surprising. After all, there was a good chance that some random game out of the 169461 I looked at would eclipse any games that were already well-known for containing a lot of young players. Like, for example, the all-rookie lineup the Houston Colt .45s fielded near the end of the 1963 season.
So I went and determined the average age of each team’s lineups in all those games (and we are talking about 338922 possibilities) and here are the two youngest starting lineups (and ages will be expressed throughout this article as YY.DDD: the number of years followed by the number of days).
Read the full article here: http://www.retrosheet.org/Research/RuaneT/retro_fun4.htm#A140505
Originally published: May 6, 2014. Last Updated: May 6, 2014.