  We calculate the average multiplicity of jets in e+e- annihilation as a
function of both the jet resolution parameter, y_cut, and the thrust T. Our
result resums to all orders the leading and next-to-leading logarithms in y_cut
and 1-T, and is exact up to second order in alpha_s. This allows a comparison
between the number of jets found using jet algorithms and the ability to
distinguish different jet topologies via thrust.
