In order for you to play Simply Chess on macOS with minimal graphics settings, your computer must meet the following requirements
Operating System:
Snow Leopard 10.6.8
Processor (CPU):
1 gHz
Memory (RAM):
512 MB RAM
Graphics Card:
OpenGL 2.1+ w/ GL_ARB_framebuffer_object
In order to play Simply Chess on macOS with maximum graphics settings, you need a computer with a configuration no worse than the following
Operating System:
Mavericks 10.9.2
Processor (CPU):
2 gHz
Memory (RAM):
1 GB RAM
Graphics Card:
OpenGL 3+
Network:
Broadband Internet connection
Storage:
300 MB available space