I have 16 different T206 backs in the three Chief Bender poses, also have 3 different T213 Bender backs which I include to make it 19. I do pick up a different player here or there if I think the card looks cool. I fully understand the facination with different backs and rarer issues, it's really cool lining up the backs with all the colors and variations.
T213-2, T213-3, and T213-3 fac overprint 8 Bender backs-
Edit to add the fronts- I have another T213-2 no trees Philadelphia American front so will have 6 different, you would think I would get sick of the same poses but it is just the opposite.