This is primarily in response to the developing discussion in the ZooChat Challenge North America 2020 thread, which I didn't want to contribute to, since (a) I won't be playing, and (b) I think there are wider points to be made. Having played four years of the Global Challenge (and observed other challenges), and having put a certain amount of thought into why I thought some years were more fun or successful than others, here are my two key conclusions: (please note that whenever I say 'fun' I mean 'fun for me' Long lists are not fun For two reasons. But they are both basically the same reason: book keeping is not fun. Firstly, it's not fun to have to write and format long lists from individual zoos. Obviously certain zoos will always defy this, but we want to avoid it as much as possible. Secondly, it's not fun to have a list so long that you can't keep a general track of it. If I have to note down every single eligible animal at a zoo and then search my own list for it later, that's not fun. I should have a rough sense of what is on there. For practical purposes I think this means having a target winning number of around 100. It should be obvious what counts I don't want to be stood in front of an exhibit not knowing if that animal qualifies or not. Because if I don't I have to note the species and check later. And again, book keeping isn't fun. So categories should be firstly clearly defined and secondly relatively well known. It's good to encourage people to look for things that might otherwise be overlooked, but not at the cost of 'fun'. That's why we tend to focus on mammals and not fish. ..... If I may I'd like to take a look at specific examples and how they passed or failed these criteria: Ungulates: For me ungulates ending up being quite frustrating because of following the Groves splits. Especially as an 'Asian' player it was often very hard to know what stuff was to 'sub-specific' level. So it failed the second test. The winning number ending up not being that high so the first test was fine. Passerines: Waaaaaaay to many species. I gave up on this one. There were also some times when I didn't know on the spot if something was a passerine or not, but I feel like that's on me. So the second test is fine. Carnivores: Passed both tests. Amphibians: Passed both tests For me both of these challenges were perfect in terms of what I am discussing Reptiles (UK Challenge): From the outside this looked absolutely hellish to me. Too many species. Primates (Europe): Seemed fine, and ironically I kept track of my list when I was back for the summer that year but it was so surprisingly noncompetitive I didn't post it. Island Endemics: This was a clear case of the second rule being violated. For birds and reptiles and fish this would have been so hard for me. South America: Too many species, but obviously well defined. ...... This post isn't totally aimed at the NA Challenge, and I think it might be useful to get the opinions of other regular 'players' to see what people actually want. I am sure there are people who disagree, but I wonder if I speak for a majority or not.