george barnard wrote:Babe and Red come to mind.
There are also classes of nickname--they vary, but according to a specific pattern. I'm not sure if these would count. I'm thinking of players named for a college they attended: Columbia Lou Gehrig, Gettysburg Eddie Plank, Frank Frisch, the Fordam Flash, etc. I wonder if those should be counted.
We also have names based on ethnicity. There were lots of German players earlier on, with names like Dutch, Hans, Honus, or Germany that emphasized that heritage. We also have Irish Meusel, and a few other Irish names. Also, some Jewish-emphasis names. Maybe Dutch is the most common German-oriented names.
Almost any native American player who stuck around was soon named Chief.
But on the whole I'd go with "Red" as the most common such nickname. A quick search through the SOM database reveals 8 position players named Red, and seven pitchers. It might be hard to top that with another name.
For example, if I'm counting right, there are 4 distinct position players named Babe and two pitchers. Of course, one of those hitter /pitchers is the same guy. A HOF quality pitcher and pretty fair hitter named Ruth.