Is this the map you mean?
http://eu.mapscompany.com/shop/maps-...p-tokyo-borch/
Kodansha atlas shows you each of the numbered blocks in each cho/district. It even shows you the numbers of many of the buildings, this allows you to pinpoint your destination, or at least make a decent guess.
The Borch map is extremely vague in comparison. I would neither use it myself nor recommend it.
In comparison, a sample of the Kodansha map:

And a sample address: Senshu University, 3-8 Kanda Jinbocho, Chiyoda, Tokyo 101-0051, Japan
The map shows the Kanda Jinbocho (3) area. Within this area are different blocks. Up at the top, between blocks 6 and 10 is block 8. (8th block of the 3rd area in Kanda Jinbocho)