Distribution of probability per trigger hadron of number of jets with $R=0.4$ and $p_{\rm T,jet}^{\rm ch}>15$ GeV/$c$ recoiling from a high-$\pT$ hadron (TT{20,30}) at midrapidity ($|\eta_{\rm jet}|<0.5$), for MB and HM pp collisions at $\sqrts=13$ TeV. Left panels: ALICE data; right panels: simulations at the particle level with PYTHIA 8 Monash tune. Lower panels show the ratio HM/MB. The insert in the lower panels has magnified vertical scale to show the ratio of probabilities to observe a single jet.