Precision determination of $\alpha_S(m_Z)$ from thrust data

I will present an extraction of the strong coupling constant, $\alpha_S(m_Z)$, from thrust data using Effective Field Theory techniques. Our calculation yields one of the most precise measurements of $\alpha_S(m_Z)$ to date. We perform a simultaneous two parameter fit to all available data at energies $Q=35$ GeV to $207$ GeV. We find $\alpha_s(m_Z)=0.1135 \pm (0.0002)_{\rm expt} \pm (0.0005)_{\rm hadr} \pm (0.0009)_{\rm pert}$, with $\chi^2/{\rm dof}=0.91$, where the displayed $1$-sigma errors are the total experimental uncertainty, the hadronization uncertainty, and the perturbative theory uncertainty, respectively.