  The D-brane counting of black hole entropy is commonly understood in terms of
excitations carrying fractional charges living on long, multiply-wound branes
(e.g. open strings with fractional Kaluza-Klein momentum). This paper addresses
why the branes become multiply wound. Since multiply wound branes are T-dual to
branes evenly spaced around the compact dimension, this tendency for branes to
become multiply wound can be seen as an effective repulsion between branes in
the T-dual picture. We also discuss how the fractional charges on multiply
wound branes conspire to always form configurations with integer charge.
