I bought a Mac a year ago. On my PC, when it is running a process that takes a while, I can play Freecell while I wait. On the Mac, I can play chess. It is one of the utilities that comes with the operating system.
One serious fault is that it does not allow the pawn to be promoted to anything except a queen. Other than that, it complies with all the rules of chess AFAIK.
I recently checked out Shredder, but when I tried to open the demo on my Mac, I got an error message saying the file was broken. That’s not a good way to sell downloads. What if I buy the download and it does not work, either?
The chess utility has limited capabilities. Like, I cannot replay a game, but I can save one. I set it at an easy level where it figures three moves ahead. When I set it to figure for one second per move, it is difficult and also takes much longer some times.