I find it odd that Reulbach's name is brought up repeatedly (rightfully so), and nobody else has mentioned fellow Cub Hippo Vaughn.
Stats are almost identical to Reulbach's, in a somewhat more hitter friendly era. Won 20 or more games 5 times, on Cubs teams inferior to the ones Reulbach pitched for.
Won the pitching triple crown in 1918. 2.49 Lifetime ERA.
