Notes. A stands for the capture of planets 1, 2 in the 4/3 MMR, B for the capture of planets 2, 3 in the 3/2 MMR, and C for the capture of planets 3, 4 in the 4/3 MMR. I run 6000 N-body simulations varying initial conditions, 5758 of which were captured in the 3:4:6:8 resonant chain. For each possible order of capture, I give the number of simulations that were captured in this order, and the statistics of captures (percentages and 1σ confidence interval) around each equilibrium. The mean values (right column) are computed assuming an equal probability for each capture order. The system is currently observed around the red equilibrium (the corresponding row is highlighted in red).