Fraction of events for which the $t_{\rm{ev}}^{\rm{Best}}$ is provided exclusively by the T0, no matter if T0A, T0C or T0AC (circle), or exclusively by the TOF (square) or a combination of the two (green) in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$= 2.76 TeV. | ![](https://alice-publications.web.cern.ch/sites/default/files/papers/3172/Eff_plotBestPbPb-23300.png ) |