Search for proton excess in primary vtx: Pythia 6
This is a plot of the average charge versus kaonicity for tracks in primary vertex. In the Golden mode there is a clear trend towards a positive excess at large kaonicity which means kaon (or proton) is favored over pion hypothesis.
Both the Pythia 6 and Pythia 5 show this effect at a slightly larger level than the data. Except there are several bins where the MC differs dramatically with the data.