That explanation was not the result of extensive tests, but, rather, a theory that I came up with in the back of my mind and never saw contradicted in any of my experiences. In particular, it gave a reasonable explanation of why Mike's Chapel is ineffective at deity plus 3 and 4. That being said, there weren't that many times when I was checking the effects of contentment structures, because I stopped building them and relied on a 40-50% luxury rate.
Black hats exhibit strange behaviors. If you have 2 left over after luxuries, Bach's may not fix them. If, however, you move a unit outside your city, the 2 unhappy faces will turn your black heads to red, which can then be fixed by Bach's! I once captured the city with Shakespeare's Theater at deity plus 3, and it would still have unhappy (but I'm not sure if there were any black hats) citizens after all was applied (in the absence of luxuries, of course). Another (slightly less) strange thing is that the happiness window and your citizens at the top of the screen don't always agree. Sometimes, the citizens above your worker allocation tiles will be red, while the last row of the happiness window will show them black.
Given these strange behaviors, the observation that my theory on the subject isn't entirely accurate isn't all that surprising, nor is the fact that another anomaly exists. You might try checking if the cities suffering more unhappiness happen to be the ones that are penalized extra by the riot factor (I'm pretty certain the find-city option lists all the cities in order, and you are probably far enough into the game that you have seen all ai cities).
I haven't really cared to look into the matter of black hats further, because I doubt that there is a discovery that can be more cost-effective to deal with black hats than luxuries (and Bach's). Also, the last D+n game I played was whatever the last succession game was.
Black hats exhibit strange behaviors. If you have 2 left over after luxuries, Bach's may not fix them. If, however, you move a unit outside your city, the 2 unhappy faces will turn your black heads to red, which can then be fixed by Bach's! I once captured the city with Shakespeare's Theater at deity plus 3, and it would still have unhappy (but I'm not sure if there were any black hats) citizens after all was applied (in the absence of luxuries, of course). Another (slightly less) strange thing is that the happiness window and your citizens at the top of the screen don't always agree. Sometimes, the citizens above your worker allocation tiles will be red, while the last row of the happiness window will show them black.
Given these strange behaviors, the observation that my theory on the subject isn't entirely accurate isn't all that surprising, nor is the fact that another anomaly exists. You might try checking if the cities suffering more unhappiness happen to be the ones that are penalized extra by the riot factor (I'm pretty certain the find-city option lists all the cities in order, and you are probably far enough into the game that you have seen all ai cities).
I haven't really cared to look into the matter of black hats further, because I doubt that there is a discovery that can be more cost-effective to deal with black hats than luxuries (and Bach's). Also, the last D+n game I played was whatever the last succession game was.
