It's been a while since I did much work on English checkers. But I hurt my foot a few months ago and was unable to walk without crutches for a while, so I decided to do some of the checkers projects that I had been putting off. I re-compressed the 10-piece db using better compression techniques to a smaller size. It used to be 214gb, and now it is 102gb. It's small enough that it can be hosted on a file server. You will find links to download it at the kingsrow web page. It takes a while to download. On a good day it takes me a few hours, but sometimes it will take a day or longer. There are a lot of large files, so it's a bit of a PITA, but it's free
I re-built most of the opening book using a fast modern computer and the 10pc db. It should be more accurate now than before. Thanks to everyone that sent me corrections in the past, particularly Jim Loy and Alex Moiseyev who each sent me several important corrections. I also merged the data from the auxiliary 'book10' opening book file into the standard book.
I also fixed some bugs in CheckerBoard. You will find links to install the newest version at the kingsrow page.
For you Italian draughts players, I built a full 10-piece db for this game. It took only 2-1/2 months using a single workstation. When I built the English 10pc db in 2005 it took almost a full year using 4 and sometimes 5 computers. New versions of kingsrow for Italian draughts, with a new opening book, and links to download the full Italian 10pc db are at the kingsrow Italian web page.
-- Ed
http://edgilbert.org/Checkers/KingsRow.htm
On one occasion I suggested Ed to adjust a little bit algorithm to reconsider evaluation of specific type position, and after a lot of testing he accepted my proposal which improved program performance.
