Originally Posted by
Mr IGH
I just measured my Tiagra double cranks, if he used the inner ring position on the cranks and flips the Shimano Alfine cog inward he'll be within a millimeter or two of perfect chainline.
In addition to the cranks themselves, with square taper bottom brackets the spindle length and taper (ISO vs JIS) will also affect chainline. Splined bottom brackets fortunately do not have taper, but I'm not sure if they have different spindle lengths.
If the OP really wanted to perfect the chainline he could also get a mm or two of additional adjustment by using a non-Shimano cog. There's a table for adjusting chainline via cog selection here:
http://www.hubgear.net/sprockets.html