Basically, it is easy to compile all non-orthogonal draughts variants according to rules. They can be divided into Frisian system rules and franco-italian systen rules; the difference is that Frisian…
Fun fact: @IvaMiMarc is spreading false news, and he is a liar. Here is a prove. It is in 1827 (55 years earlier than @IvaMiMarc indicated, btw.) than well known chess master and theoretician Alexan…