Type 'easy' or 'hard' to begin the quiz. Easy is a 15-degree grid, hard is a 10-degree grid. Then, try to name the SECOND LARGEST city in each grid square. To name a city, you must first click on the grid square to make it have a GREEN border. Then, type in the city answer for that square followed by a '.' (a period). You are given a score from 0 to 100 based on your answer's population compared to the 2nd largest city accepted in that square (100 being you named the 2nd largest city). If you guess the largest city it will be based on the ratio of the 2nd largest city's population to the largest.
At the end of the quiz the 2nd largest city will show in each unanswered square, and for those answered the 2nd largest city will be listed next to your score if you didn't answer it.
Quiz Takers 
No Osaka, Buenos Aires, Manila, Chicago, Paris etc… but Chinese cities like Urumqi and Shijiazhuang are? I mean, I get it… there are a lot of people in China, but something just seems off there.
These cities’ city proper population is not nearly as large as their metro population – and on my site city proper is generally used.
If you don’t live in China, or study China for a few days before, it’s impossible.. who knows which is which outside the well known ones.
Metro pops would be a little easier and less China centric
got 71/100, china is brutal + a couple of misclicks and mixing up where Hyderabad and Bengaluru
WHERE IS OSAKA, SOME SOURCES CONSIDER IT TOP 10 IN THE WORLD
city proper populations per citypopulation.de Japan census it’s only 2.7 million
Nice Quiz, got 71, missclicked 1 in egypt 3 in India, but china is very difficult in the Shanghai and Guangzhou region with the many Markers.