Improvements in $t\bar{t}$ modelling using NLO+PS Monte Carlo generators for Run2

Monte Carlo generators at next-to-leading order (NLO) precision in QCD matched to a parton shower (PS) have been extensively used by ATLAS to model top-quark pair production. During Run 2 these NLO+PS configurations have been updated to provide improved modelling and reduced systematic uncertainties. This note provides a summary of these improvements. The studies are performed using published unfolded data at a centre-of-mass energy of 13 TeV.