Originally Posted by
ThermionicScott
ON EDIT: Think I figured it out -- one extra tooth increases the circumference of the cog by one half-link. Half of that is on the inside of the chain loop and doesn't contribute to the chain length. The other half contributes equally to the top and bottom of the chain.
I would think it would change the circumference one full ink (i.e., the pin-to-pin distance or 1/2"). I must ponder this in my heart.