You're standing in front of the locked library doors, waiting for it to open at 1 pm Sunday afternoon, so you can get at least an hour of microfilm research in before you head to a Superbowl party.
Four more city directories down. The 1914 roll was incomplete - beginning with names starting with "Deb". Luckily, I found my one Blatt ancestor in the business section, so I know where his tailor shop was that year. While he wasn't living at the same address in 1915 as he was in 1913, the exact year he moved isn't a major concern.