Effective Field Theories + jets = precision physics

In this talk I will give an overview of our recent developments in the theoretical description of massless and massive event shapes. In the massless case I will focus on thrust and C-parameter, showing results for resummation at N3LL order, and the analytic treatment of power corrections. I will also present the results for the determination of the strong coupling constant. For massive event shapes I will discuss the novel theoretical treatment of primary and secondary heavy quark production. As an application, I will show a "determination" of the top mass from Pythia-simulated data. This serves to clarify the following long-standing question: which short-distance mass scheme is used in Pythia?