Nathan, if you look at a simple sheet of maille, say 8" x8" with the exception of the rings around the four outter edges ( which will only be attached to three other rings ) all the rings in the sheet will be attached to four other rings, two in the row above and two in the row below. In an expanding row, while you will still attach the rings to two rings in the row above, when installing the next row below you will attach three rings ( how much you grow or expand you pattern will depend on the frequency of rings with three rings attached at the bottom, every ring will make for big expansion, every other a bit less, every 3rd or 4th less ect. still depending on how much you need to add ) thus adding a ring into the count every time you do it and the row below it will thus be that much farther around as well ( this can be done in reverse, you can have rings go through three rather than two rings in the row above them thus reducing your count ).