I am all for taking a critical look at American systems and their effectiveness of the response, but the ranking by the case numbers is naive, misleading and unproductive.
And so ranking countries by size of outbreak seems reasonable to me.
Edit: Here you go, here's one corrected for day of 100th case.
- Amount of testing
- Sampling process of testing - i.e. Policies that govern whether someone should be tested or not. Each country has their own policy.
- Demographics, especially age
- Still shows total cases, should be cases/capita
- Some effects of weather/humidity
Remember the virus has an incubation period of around 2 weeks. China's numbers appeared to be increasing exponentially for 2 weeks after the lockdown, but those were mostly people infected before the lockdown.
Any country with sufficient testing that's managed to bring the growth rate below exponential is worth an enormous amount of attention, because we seem to have many countries who have taken action yet failed to stop exponential growth.