COMPLETELY UNSCIENTIFIC ANALYSIS
One of the frustrating things in the Sim to me is the ineffectiveness of old-time base stealers. You just can't use them anywhere near their potential for stealing, their caught stealing percentages are too high.
So, why aren't old-time catchers' arms better? Just doing a basic search of A+ arms for players who were primarily catchers and had at least 400 PA/162, here's the breakdown of how many there are per 20-year period (I did not allow for multiple occurances of the same player/season, as a quick look revealed there aren't that many):
1885-1900 2
1901-1920 17
1921-1940 29
1941-1960 16
1961-1980 154
1981-2000 92
Expansion undoubtedly had an effect starting in 1961, as did the scales tipping toward pitching resulting in more risks on the basepaths. Still, looking at the deadball era, if basestealers were caught so often why aren't there more A+ arms?