How to count plies?
When I was a kid and we had computer chess programs, there was no such thing as 0-ply. 1-ply meant that the program looked at each possible move (that’s the ply), evaluated the position, and then returned the result (i.e. the best move). 2-ply meant that it looked at each possible move and each possible response, etc. Between backgammon and chess, there is much more reason in backgammon to evaluate a position statically, on its merits alone, as compared to chess where I’ve never had the experience of asking a computer to say who is winning and by how much (remember I was a kid back then). It seems that nowadays, when you ask a backgammon program to make a move, it does a search of all legal moves (“1-ply”) and then evaluates each position statically (“0-ply”). A 1-ply search but a 0-ply evaluation, if you will. When it comes to a doubling decision, the Gnu count is clearly more accurate, because “Snowie 1-ply” doesn’t do any lookahead at all when deciding. So, while it’s possible to ar
