On the custom statistic reports, a player's current age.
And why a team of old position players can be a pretty big problem.
If the Yankees could send their current roster back in time to a previous season, which one would they choose?
Old players are contributing less to teams than they have in years, but a few veterans are bucking the trend.
How much should the age of a team’s present roster affect our forecasts for its future success?
A look back at a classic study of pitcher injuries.