1/8 [of a mile] is one block
where
The third most populous city in America.
Except for the blocks between Madison/Roosevelt (1/12), Roosevelt/Cermak (1/10) and Cermak/31st (1/9)
Some of those are iffy, IMHO.
The Eisenhower screws up the blocks between Madison and Roosevelt pretty much all the way across Chicago, such that it's almost impossible to say exactly what the blocks
are between the two. Go down Austin Blvd, for example (perhaps the least messed up by the Ike), and you hit the following cross-streets: Adams, Jackson, (Van Buren), Harrison, Garfield, Arthington, Fillmore, Roosevelt. That's the typical eight blocks, despite having gone from 0 North/South to 1200 South.
Between Roosevelt and Cermak, things are a little squirrely, too. 17th Street basically doesn't exist anywhere west of California (except for a one-block tidbit at Kostner), and it's only one block between 16th and 18th. A similar thing happens at 20th Street: West of Racine, Cullerton basically takes the place of 19th Place, and then the grid basically skips to 21st Street. It's basically eight blocks, despite having gone from 1200 South to 2200 South.
Take a drive down Kedzie from Cermak, and you hit the following cross-streets: 23rd, 24th, 25th, 26th, 27th, 28th, 30th, 31st. That's the typical eight blocks, despite having gone from 2200 South to 29th Street doesn't exist anywhere west of Racine. So it's basically eight blocks, despite having gone from 2200 South to 3100 South.