No, it’s more likely just a natural consequence of the tempo of play and tactics employed in high level handball games.
The model’s fit for the home team’s goals looks much better overall, but it still appears to underestimate the frequencies of the two most common values (30 and 31).
Still, as you suggested, if I were to reallocate some goals to the neighboring classes the plot would be fine.
Do you think this is cause for concern? I’ve read some papers (https://www.statlab-unisa.it/cladag2023/wp-content/uploads/simple-file-list/IS22-4058-12087-3-DR.pdf and https://journals.sagepub.com/doi/full/10.1177/22150218251313937) arguing the Poisson may not be a good fit for handball data because it can’t accommodate under dispersion. The authors suggest the Conway-Maxwell-Poisson but it was not implemented in Stan (Conway-Maxwell-Poisson Distribution).