It seems to me that this particular set has a significant number of players with A steal ratings.
Previously there was a mini-discussion re. Tinker to Evers to Chance, and that for all their notoriety, they really didn't turn that many double plays in that combination. Besides the Cubs pitchers being very good (at least in 1906) and thus not allowing too many baserunners, I now have to wonder if a large percentage of those few batters who did reach base then attempted to steal second base, so that regardless of whether they were successful or not (and as I indicated in an earlier post, the Cubs catchers did throw out a large percentage of base runners), there just weren't that many occasions when there would be a runner on first base that could get doubled up.